The Lab Library

Nutrient shortfalls

• HDL responds far more to metabolic state than to any single nutrient -- it falls with insulin resistance and rises with physical activity, and no supplement moves it reliably.
• Omega-3s raise HDL modestly; refined carbohydrate lowers it.

Exposures

• Smoking lowers HDL and impairs its function; trans fats lower it directly.
• PFAS exposure associates with altered lipids in the C8 cohort, including cholesterol -- one of the six conditions the C8 Panel named.

Gut

• Microbiome-driven changes in bile acid handling reach HDL through reverse cholesterol transport.

Detox capacity

• HDL carries cholesterol back to the liver for disposal in bile -- so its job is a clearance job, and hepatic function is part of whether it works.

How it cascades

• A LOW HDL WITH HIGH TRIGLYCERIDES IS THE INSULIN-RESISTANCE PATTERN, and it is more informative than either number read alone. That combination is the signal to look at fasting insulin, ALT and uric acid.
• Raising HDL pharmacologically has repeatedly failed to deliver the benefit its association predicted -- which is a caution about treating it as a target rather than a readout.

What people often feel when it runs high

• Silent, and NOT automatically good news. ⚠️ HDL IS ONE OF THE CLEAREST U-SHAPED MARKERS IN THE PANEL: very high HDL (roughly above 80-90 mg/dL) has been associated with WORSE outcomes in large cohorts, not better. The drugs that raised HDL failed to reduce events. HDL is a marker of the process, not a lever to pull.
• Heavy alcohol intake raises HDL, which is one reason a 'good' HDL is not self-explanatory.

What people often feel when it runs low

• Silent. HDL produces no sensation at any level.
• A low HDL travels with the metabolic pattern that does produce symptoms -- central weight, the afternoon crash, raised triglycerides, rising blood pressure.
• Smoking, physical inactivity and very low-fat high-refined-carbohydrate diets all lower it.

Patterns it travels in

• HDL LOW + TRIGLYCERIDES HIGH is the metabolic signature, and the TG:HDL RATIO is a better read on insulin resistance than either number alone.
• HDL LOW + APOB HIGH + WAIST UP + GLUCOSE UP -- the metabolic-syndrome cluster. Any three carry more meaning than one.
• ⚠️ DO NOT CHASE HDL AS A TARGET. Every pharmacological attempt to raise it failed to improve outcomes. Treat a low HDL as a signal to address triglycerides, insulin resistance and activity -- which raise it as a side effect of fixing something real.
• HDL HIGH + heavy alcohol intake -- ask, rather than congratulate.
• HDL LOW + TSH HIGH -- thyroid again, before diet.

Ingredients with evidence in our library

• Physical activity, and stopping smokingsolid -- The two interventions that actually move HDL, and neither is purchasable. Framed honestly: they move it because they change the underlying process, which is the only reason HDL moving is worth anything. (206 studies in our library, 37 in people)
• Extra virgin olive oil (oleic acid + polyphenols)emerging -- Our library holds olive oil polyphenols improving HDL cholesterol and supporting lipid metabolism maintenance -- one of the few dietary interventions with a direct HDL endpoint rather than a total-lipid one. (2 studies in our library, 1 in people)
• Beta-glucan (oat/barley)solid -- 5 rows, 4 human -- systematic review and meta-analysis in dyslipidaemia. (5 studies in our library, 4 in people)
• Astaxanthinemerging -- Supplementation measured on glycaemic control and lipid profile together in human trials. (2 studies in our library, 2 in people)
• Saffron, goji and pycnogenolemerging -- Each carries 2-3 human-typed rows on lipid profile in our library -- small, consistent, and not to be oversold as HDL-specific. (8 studies in our library, 6 in people)
• ⚠️ Niacin -- the cautionary talecontested -- Raises HDL substantially and failed to reduce cardiovascular events in two large outcome trials (AIM-HIGH, HPS2-THRIVE) while causing more harm. It is the clearest proof available that HDL is a marker and not a target, and it belongs on this page for that reason. (2 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Choline shortfall raises triglycerides by the liver route -- without choline the liver cannot export fat as VLDL, so fat accumulates there instead. This is the cleanest link between a lipid panel and liver status.
• Omega-3 shortfall raises triglycerides; above roughly 3 g/day of combined EPA and DHA they fall 15 to 30%, while lower doses do little.
• Magnesium is a cofactor for lipoprotein lipase, the enzyme that clears triglycerides from the blood.

Exposures

• Fructose and alcohol are the two most reliable dietary drivers of triglycerides, and both work through the same place -- de novo lipogenesis in the liver.
• Trans fats lower HDL and raise LDL simultaneously, which almost nothing else does.

Gut

• The microbiome shapes bile acid signalling and short-chain fatty acid production, both of which influence hepatic lipid handling.
• Soluble fiber binds bile acids so they are excreted rather than recycled, forcing the liver to use cholesterol to make more -- the mechanism behind fiber's effect on LDL.

Detox capacity

• The liver builds and clears these particles, which is why lipids and liver enzymes move together far more often than either panel suggests on its own.

How it cascades

• TRIGLYCERIDES ARE A LIVER MARKER AS MUCH AS A LIPID ONE. Excess fructose or alcohol -> de novo lipogenesis -> hepatic fat -> triglycerides rise AND ALT rises AND uric acid rises. Three panels, one process. If triglycerides are up, read ALT and GGT beside them.
• The TRIGLYCERIDE-TO-HDL RATIO is the most useful number on this panel and is not printed on it -- it tracks insulin resistance more closely than either value alone, and it moves years before fasting glucose does.
• High triglycerides also shift LDL toward the smaller, denser particles that ApoB counts -- which is why a normal LDL-C with high triglycerides can still mean a raised particle number.

What people often feel when it runs high

• HIGH TRIGLYCERIDES: silent at ordinary levels. Very high levels (roughly above 500 mg/dL) can cause abdominal pain and pancreatitis, and at extreme levels the blood plasma looks visibly milky.
• The symptoms that actually travel with raised triglycerides belong to the metabolic pattern behind them -- the post-meal crash, central weight, rising blood pressure, fatty liver.
• Small yellowish deposits on the eyelids or in skin creases point at markedly abnormal lipids and are worth noticing.
• ⚠️ TRIGLYCERIDES ARE THE MOST DIET-RESPONSIVE MARKER ON THE WHOLE PANEL and the most sensitive to what happened in the last few days -- a fasting sample matters here more than for anything else.

What people often feel when it runs low

• Very low total cholesterol alongside low albumin and unintended weight loss points at absorption or liver capacity, not at good health.

Patterns it travels in

• TRIGLYCERIDES HIGH + HDL LOW is the metabolic signature, and the TG:HDL RATIO is one of the best cheap proxies for insulin resistance available on a standard panel. It needs no extra test and is almost never calculated.
• TRIGLYCERIDES HIGH + ALT HIGH -- two readouts of one process. Triglycerides frequently move FIRST, which makes them an earlier warning than the liver enzyme. Our library holds 66 rows pairing triglycerides with liver fat and 25 on fructose restriction, 12 of them human.
• TRIGLYCERIDES HIGH + APOB HIGH + LDL-C NORMAL is the small-dense pattern -- many small cholesterol-poor particles. LDL-C alone reads normal and misses it entirely.
• TRIGLYCERIDES HIGH + FASTING INSULIN HIGH + URIC ACID HIGH is the fructose picture: fructose is the one common sugar whose metabolism generates urate directly and drives hepatic lipogenesis.
• TOTAL CHOLESTEROL HIGH + TSH HIGH -- rule out the thyroid before treating it as diet. Hypothyroidism slows LDL-receptor clearance and correcting it corrects the lipids.
• ⚠️ A RECENT VERY LOW-CARB DIET, A COLD, PREGNANCY, OR ALCOHOL IN THE LAST 48 HOURS all move these numbers. Ask before interpreting.

Ingredients with evidence in our library

• Omega-3 (EPA/DHA)solid -- 44 rows, 34 human -- the most reliable and most dose-dependent triglyceride-lowering intervention in this library. This is the endpoint on which fish oil's evidence is strongest by a distance, more so than for anything else claimed for it. (44 studies in our library, 34 in people)
• Cutting fructose and alcoholsolid -- The two largest levers, and both are subtractions. Our library's fructose-restriction rows measured liver fat and de novo lipogenesis falling together (12 human-typed). Alcohol raises triglycerides directly and quickly. (25 studies in our library, 12 in people)
• Beta-glucan (oat/barley)solid -- 11 rows, 7 human -- meta-analytic evidence in dyslipidaemia. Viscous fibre binds bile acids so the liver must clear more particles to rebuild them. (11 studies in our library, 7 in people)
• Saffronsolid -- 10 rows, 8 human -- glycolipid metabolism and blood pressure in metabolic syndrome. Unusually high human proportion for a botanical. (10 studies in our library, 8 in people)
• Probiotics and synbioticsemerging -- 15 rows, 6 human, plus 7 prebiotic rows -- anthropometric and lipid outcomes measured together. (22 studies in our library, 8 in people)
• Anthocyanins (purple corn, black rice, berries)emerging -- 17 rows across both anthocyanin tags, reviewed with curcumin and resveratrol for metabolic dysfunction. (17 studies in our library, 10 in people)
• Artichoke leaf extractemerging -- 13 rows -- systematic review evidence in fatty liver, where the lipid and liver endpoints move together. (13 studies in our library, 2 in people)
• Beta-sitosterol / plant sterolssolid -- 6 rows. Competes with cholesterol for intestinal absorption; roughly 5-15% LDL-C reduction at about 2 g/day. (6 studies in our library, 3 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Magnesium shortfall -- magnesium is a cofactor for the insulin receptor and for the enzymes that phosphorylate glucose, so low magnesium raises insulin resistance. The relationship runs both ways: high glucose increases urinary magnesium loss, which deepens the shortfall.
• Chromium and low dietary fiber both reduce the efficiency of glucose handling, fiber mainly by removing the brake on how fast glucose arrives.
• Vitamin D shortfall associates with worse insulin sensitivity in observational work; supplementation trials in people who are not deficient have been largely unimpressive, so treat this as a status to correct, not a lever to push.

Exposures

• Persistent organic pollutants and some plasticisers are associated with insulin resistance in population data -- an exposure signal on a marker most people read as purely dietary.
• Sleep loss and alcohol both raise fasting glucose independently of what was eaten.

Gut

• Microbiome composition shapes short-chain fatty acid production and incretin signalling, both of which affect glucose handling. This is one of the clearer routes from gut to a routine metabolic number.

Detox capacity

• The liver sets fasting glucose overnight through gluconeogenesis, so hepatic fat and hepatic insulin resistance move this number before the pancreas is in trouble. Read it alongside ALT.

How it cascades

• Hepatic fat -> hepatic insulin resistance -> the liver keeps making glucose overnight -> fasting glucose rises while post-meal numbers still look fine. This is why a normal HbA1c and a creeping fasting glucose can coexist.
• Fasting glucose is a late marker. Fasting insulin and triglyceride-to-HDL ratio usually move years earlier -- if this number is drifting, the process is already established.

What people often feel when it runs high

• The afternoon crash -- 'why do i crash after eating carbs', 'energy crash after eating', 'tired after eating not diabetic'. One of the highest-volume searched complaints there is, and one of the few with a cheap measurement behind it.
• Waking at 3am, often with a racing heart -- 'why do i wake up at 3am every night'. A nocturnal glucose dip triggers cortisol and adrenaline to correct it, and the adrenaline is what wakes you.
• Thirst and night urination that is new rather than lifelong.
• Hunger that returns within two hours of eating, and shakiness or irritability if a meal is late -- the 'hangry' pattern is a glucose-regulation pattern.
• Central weight that will not move on the same effort that used to move it.
• Skin tags, and darkened velvety skin in neck folds or armpits (acanthosis nigricans) -- visible signs of sustained high insulin, and often present long before glucose itself moves.
• Slow-healing cuts, and recurrent thrush or urinary infections.

What people often feel when it runs low

• Shakiness, sweating, sudden anxiety and difficulty concentrating that resolve within minutes of eating.
• ⚠️ A LOW FASTING GLUCOSE IS NOT AUTOMATICALLY REASSURING. Alongside low albumin or abnormal liver enzymes it can reflect reduced hepatic glucose output rather than good metabolic health.

Patterns it travels in

• FASTING GLUCOSE NORMAL + FASTING INSULIN HIGH is the single most valuable early combination in this entire panel, and the one a standard physical misses. Insulin rises for years -- often a decade -- to hold glucose normal. Measuring glucose alone declares that person healthy for the whole period when the problem is most reversible. If only one thing gets added to a basic panel, add fasting insulin.
• FASTING GLUCOSE HIGH + HBA1C NORMAL -- check the red cell indices before believing either. Anything that shortens red-cell lifespan (haemolysis, recent blood loss, iron deficiency in recovery) lowers HbA1c independently of glucose.
• FASTING GLUCOSE NORMAL + HBA1C HIGH runs the other way and is common with iron deficiency, B12 deficiency and in later pregnancy -- longer-lived red cells accumulate more glycation at the same average glucose.
• GLUCOSE HIGH + TRIGLYCERIDES HIGH + HDL LOW + WAIST UP is the metabolic-syndrome cluster. Any three of them together carry more meaning than any one alone, and they respond to the same lever.
• GLUCOSE HIGH + ALT HIGH + TRIGLYCERIDES HIGH is the liver's version of the same process -- hepatic fat and de novo lipogenesis. Triglycerides frequently move FIRST, which makes them an earlier warning than the glucose is.
• GLUCOSE HIGH + CORTISOL HIGH (especially morning) -- cortisol raises glucose by design. A glucose that only misbehaves during stressful periods, or that runs high on waking, points at the HPA axis rather than the pancreas.
• GLUCOSE HIGH + MAGNESIUM LOW is a loop worth breaking: magnesium is a cofactor for insulin signalling, and high glucose increases urinary magnesium loss, so each worsens the other.
• GLUCOSE HIGH + TSH HIGH -- an underactive thyroid slows glucose disposal and commonly travels with the same picture.

Ingredients with evidence in our library

• Magnesiumsolid -- Oral supplementation improved glycaemic control in older adults with prediabetes and insulin resistance. Magnesium is a required cofactor for the insulin receptor's own signalling, which is why the deficiency and the resistance reinforce each other. (9 studies in our library, 5 in people)
• Inositol (myo- and D-chiro-)solid -- Among the better-evidenced interventions in this library for glucose handling -- effective in prevention and treatment of gestational diabetes, and a mainstay of PCOS insulin resistance. Acts as a second messenger downstream of the insulin receptor. (13 studies in our library, 7 in people)
• Chromiummixed -- Modulates insulin receptor activity -- systematic review evidence. Effect is largest where intake was genuinely low, and unremarkable in the already-replete, which is the honest version of this claim. (8 studies in our library, 6 in people)
• Zincsolid -- The largest single ingredient signal on this marker in our library (18 rows). Zinc is structurally required to store and secrete insulin -- insulin is crystallised in the beta cell around zinc ions. (18 studies in our library, 9 in people)
• Saffron / crocinsolid -- Improved glycolipid metabolism and blood pressure in metabolic syndrome; unusually high human-trial proportion (7 of 8 rows). (8 studies in our library, 7 in people)
• Probiotics and prebiotics / inulinsolid -- Maternal and adult trials show improved glucose metabolism -- the gut route the cross-reference spec predicts, acting through short-chain fatty acids and incretin signalling. (23 studies in our library, 10 in people)
• Anthocyanins (purple corn, black rice, berries)emerging -- Reviewed alongside curcumin and resveratrol for prevention and management of metabolic dysfunction; slow carbohydrate absorption and improve insulin sensitivity. (20 studies in our library, 5 in people)
• Melatoninmixed -- GRADE-assessed evidence on blood glycaemic indices in adults. Note the direction is timing-dependent -- melatonin and a late meal together worsen glucose handling, so this is a nighttime nutrient, not a mealtime one. (9 studies in our library, 3 in people)
• Alpha-lipoic acidemerging -- Studied mostly in PCOS insulin resistance; improves insulin sensitivity and is the classic support for glucose-related nerve symptoms. (11 studies in our library, 1 in people)
• Vitamin Dmixed -- Serum 25(OH)D associated with islet function; supplementation improved insulin sensitivity in impaired fasting glucose. Association is stronger than the intervention effect. (13 studies in our library, 6 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Iron shortfall raises HbA1c without any change in glucose, because iron-deficient red cells live longer and accumulate more glycation. An unexplained HbA1c rise with low ferritin is an iron finding, not a glucose one.
• B12 and folate shortfall can do the same thing through altered red cell turnover.

Exposures

• Anything that shortens red cell lifespan -- including some exposures and haemolysis -- lowers HbA1c and can hide genuinely high glucose.

Gut

• Malabsorption that produces iron or B12 shortfall reaches HbA1c through the red cell route above, which is why this marker cannot be read in isolation from a CBC.

Detox capacity

• Not a detox-sensitive marker directly; its confounders are haematological.

How it cascades

• HbA1c is a measure of RED CELLS as much as of sugar. It reports average glucose over the lifespan of the cell, so anything altering that lifespan alters the result -- read it beside ferritin and the red cell indices, never alone.
• Chronic high glucose -> glycation of proteins throughout the body -> the same process this test measures is happening to collagen, lens and vessel proteins. The number is a sample of a systemic process.

What people often feel when it runs high

• Everything listed under fasting glucose, but with more time behind it -- HbA1c is a three-month average, so symptoms are usually established rather than new.
• Fatigue that is constant rather than post-meal.
• Blurred vision that comes and goes as glucose swings.
• Numbness, tingling or burning in the feet, typically worse at night.
• Recurrent infections, slow healing, and gum disease.

What people often feel when it runs low

• ⚠️ AN UNEXPECTEDLY LOW HBA1C IS A RED CELL FINDING UNTIL PROVEN OTHERWISE. It means red cells are not living the full ~120 days -- haemolysis, recent bleeding, or the rapid turnover after iron or B12 repletion. It is not evidence of excellent glucose control, and reading it that way misses the actual problem.

Patterns it travels in

• HBA1C + FASTING GLUCOSE + FASTING INSULIN TOGETHER, always. Each answers a different question -- the average, the moment, and the effort being spent to hold it. Insulin is the one that moves first and the one usually left off.
• HBA1C HIGH + MCV HIGH or LOW -- read the red cell indices first. HbA1c is only as good as the assumption that red cells live 120 days, and MCV is the cheapest check on that assumption.
• HBA1C HIGH + FERRITIN LOW falsely ELEVATES HbA1c: iron-deficient red cells are older on average and accumulate more glycation. Correcting the iron lowers HbA1c with no change in glucose at all.
• HBA1C HIGH + TRIGLYCERIDES HIGH + HS-CRP HIGH is metabolic inflammation with time behind it -- the combination that most reliably predicts the trajectory.
• HBA1C HIGH + ALT HIGH -- the liver is storing the surplus. Read this pair together rather than as a metabolic finding and a separate liver finding.

Ingredients with evidence in our library

• Saffron / crocinsolid -- The strongest human-weighted signal on this specific marker in our library -- 6 of 7 rows human, including monotherapy evaluation on glycaemic endpoints. (7 studies in our library, 6 in people)
• Zincsolid -- Supplementation moved glycaemic biomarkers including HbA1c. (6 studies in our library, 4 in people)
• Magnesiumsolid -- Improved glycaemic control in prediabetes; the same insulin-signalling cofactor role as under fasting glucose. (4 studies in our library, 3 in people)
• Chromium (with vitamin C)emerging -- Combined effect on hyperlipidaemia and hyperglycaemia measured together in human trials. (4 studies in our library, 4 in people)
• Probiotics / synbioticssolid -- Post-surgical and general adult trials show anthropometric and glycaemic movement together. (4 studies in our library, 4 in people)
• Melatoninemerging -- GRADE-assessed effect on glycaemic indices; all four rows human-typed. (4 studies in our library, 4 in people)
• Resistant starchemerging -- Mango- and banana-derived resistant starch reviewed for biochemical mechanism and human effect -- feeds butyrate production and blunts the post-meal excursion that HbA1c averages. (2 studies in our library, 1 in people)
• Time-restricted eating (dietary, not a supplement)solid -- The single most-cited intervention across these rows, and it costs nothing. Effects vary by cardiometabolic phenotype, age and sex -- it is not uniformly effective, and the trials say so. (28 studies in our library, 21 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Uric acid is not only a waste product -- it is one of the bloodstream's more significant antioxidants, so an unusually LOW value is not automatically good news.
• Vitamin C modestly increases uric acid excretion.

Exposures

• Fructose is the dietary driver that most people miss: its metabolism consumes ATP and generates uric acid directly, which is why sweetened drinks move this number more reliably than red meat does.
• Alcohol, particularly beer, both raises production and reduces excretion.
• Lead exposure impairs renal urate handling -- a genuine exposure route to a raised level.

Gut

• Roughly a third of uric acid is eliminated through the gut rather than the kidney, so gut function is a real part of the disposal picture.

Detox capacity

• The kidney handles most excretion, so any fall in filtration raises uric acid before creatinine looks abnormal -- making it an early kidney signal as much as a metabolic one.

How it cascades

• High fructose -> ATP consumed in the liver -> uric acid produced -> and the same process drives hepatic fat. A raised uric acid with a raised ALT is one metabolic story, not two findings.
• Uric acid tracks insulin resistance closely, because insulin reduces its renal excretion. It often moves before glucose does.

What people often feel when it runs high

• Sudden severe pain, redness and swelling in one joint -- classically the base of the big toe, often starting overnight.
• Kidney stones, or a history of them.
• Frequently NOTHING. Most people with a raised uric acid never have an attack, which is why it is a marker to interpret in context rather than to act on alone.
• Where it travels with the metabolic pattern, the symptoms are that pattern's -- rising blood pressure, central weight, the post-meal crash. Fructose is the shared driver: it is the one sugar whose metabolism generates uric acid directly.

What people often feel when it runs low

• No symptoms. Uric acid is the blood's most abundant antioxidant, and very low levels have been associated with worse outcomes in some neurological contexts -- one of the clearest U-shaped markers in the panel, where lower is not simply better.

Patterns it travels in

• URIC ACID HIGH + TRIGLYCERIDES HIGH + FASTING INSULIN HIGH is the fructose and insulin-resistance pattern. Insulin reduces uric acid excretion by the kidney, so the raised urate is often a consequence of the insulin, not an independent problem.
• URIC ACID HIGH + EGFR FALLING -- the kidney clears about two-thirds of uric acid, so reduced filtration raises it. Rising urate can be the earlier of the two signals.
• URIC ACID HIGH + BLOOD PRESSURE RISING has a plausible mechanism (endothelial nitric oxide) and remains genuinely contested as a causal chain rather than an association. Worth stating as contested, not as fact.
• URIC ACID LOW + LOW ANTIOXIDANT STATUS -- read alongside carotenoid status rather than as a stand-alone win.
• ⚠️ DIURETICS, LOW-DOSE ASPIRIN, ALCOHOL AND A RECENT FAST all raise uric acid. Check those before concluding anything dietary.

Ingredients with evidence in our library

• Vitamin Csolid -- The largest ingredient signal on this marker in our library by a wide margin -- vitamin C is uricosuric, competing with urate at the kidney's reabsorption transporter, so more is excreted. Effect size is modest and consistent rather than dramatic. (20 studies in our library, 5 in people)
• Folate, B6 and B12emerging -- Dietary intake measured explicitly in relation to hyperuricaemia -- an inverse association rather than a trial result. (6 studies in our library, 3 in people)
• Cutting fructose, especially liquid fructosesolid -- The strongest lever and not a supplement. Fructose metabolism consumes ATP and generates urate directly -- it is the only common dietary sugar that does this. Sugar-sweetened drinks and fruit juice are the concentrated source. (138 studies in our library, 75 in people)
• Molybdenum -- the cofactor worth understanding backwardsemerging -- Molybdenum is required by xanthine oxidase, the enzyme that PRODUCES uric acid. This is a cofactor to understand, not to supplement for this purpose, and the direction is the opposite of the usual assumption. (2 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Iodine is the raw material for thyroid hormone and selenium runs the enzymes that convert T4 to active T3 -- iodine without selenium is the imbalance to avoid, not iodine itself.
• Iron shortfall impairs thyroid peroxidase, so unresolved low ferritin can hold thyroid function down independently of iodine.
• Zinc and vitamin A are both required for thyroid hormone signalling at the receptor, which is downstream of anything TSH can show.

Exposures

• Fluoride, bromide and perchlorate compete with iodine for uptake at the thyroid.
• PFAS: NASEM specifically recommends thyroid testing at higher exposure levels -- an unusual case where a chemical-exposure guideline names this exact marker.

Gut

• A meaningful share of T4-to-T3 conversion depends on gut bacterial enzymes, so microbiome disruption reaches thyroid status by a route TSH cannot see.

Detox capacity

• The liver performs much of the T4-to-T3 conversion, so hepatic function sits between a normal TSH and how someone actually feels.

How it cascades

• TSH is a PITUITARY signal, not a thyroid measurement -- it reports what the brain is asking for. It can sit in range while conversion to active T3 is poor, which is why free T3 and T4 answer a different question.
• Chronic stress -> raised cortisol -> reduced T4-to-T3 conversion and more reverse T3 -> normal TSH, low functional thyroid activity. Read TSH beside cortisol before concluding the thyroid is fine.

What people often feel when it runs high

• HIGH TSH MEANS AN UNDERACTIVE THYROID -- the counterintuitive part people get wrong constantly. TSH is the pituitary shouting; the louder it shouts, the less the thyroid is delivering.
• Cold all the time, especially hands and feet, and needing more layers than everyone else in the room.
• Fatigue that sleep does not fix -- 'why am i always tired no matter how much i sleep'.
• Weight gain of a few kilos with no change in eating, and difficulty losing it.
• Constipation, dry skin, brittle nails, and hair thinning or loss of the outer third of the eyebrow.
• Brain fog, slowed thinking, low mood -- routinely mistaken for depression, and one of the reasons thyroid belongs in a first panel.
• Heavier or longer periods; reduced fertility.
• Muscle aches, cramps, and slow relaxation of reflexes.
• Hoarse voice, puffiness around the eyes.

What people often feel when it runs low

• LOW TSH MEANS AN OVERACTIVE THYROID -- or too much thyroid medication, which is the commoner cause in anyone already treated.
• Racing or irregular heartbeat, palpitations, waking at night with the heart pounding.
• Anxiety, inner restlessness, 'wired but tired', tremor in the hands.
• Heat intolerance and sweating more than everyone else.
• Weight loss despite a good appetite; loose stools.
• Trouble falling asleep, and lighter sleep.
• ⚠️ SUPPRESSED TSH IS NOT A HARMLESS OVERSHOOT. Over years it costs bone density and raises atrial fibrillation risk -- it needs a dose conversation, not reassurance.

Patterns it travels in

• TSH ALONE IS NOT A THYROID PANEL. TSH plus free T4 plus free T3 plus TPO antibodies is. TSH can sit in range while free T3 is low, which is the commonest reason someone with every symptom is told their thyroid is fine.
• TSH HIGH + FREE T4 NORMAL is subclinical -- the pituitary is compensating and succeeding. This is the window where nutrient status (selenium, iodine, iron, zinc) is most worth checking, and where our library's evidence is strongest.
• TSH HIGH + TPO ANTIBODIES POSITIVE names the mechanism as autoimmune, which changes what is worth doing. Antibodies frequently precede the TSH change by years.
• TSH HIGH + FERRITIN LOW is a genuinely under-recognised pair -- thyroid peroxidase is a haem enzyme and needs iron to work. Iron deficiency both causes thyroid symptoms and blunts the response to thyroid replacement. Our library carries this explicitly (iron and ferritin deficiency in women with hypothyroidism and chronic lymphocytic thyroiditis).
• TSH HIGH + LDL/APOB HIGH -- hypothyroidism slows LDL-receptor clearance. Check thyroid before treating the lipids as a diet problem; correcting the thyroid often corrects the lipids.
• TSH HIGH + SODIUM LOW + CORTISOL LOW is a pattern that needs a clinician, not a supplement plan.
• TSH NORMAL + FREE T3 LOW + REVERSE T3 HIGH is the non-thyroidal illness pattern -- seen in acute illness, prolonged energy restriction and over-training. The thyroid is fine; the body is deliberately down-regulating. More food and more rest, not more iodine.
• ⚠️ BIOTIN INTERFERES WITH THE ASSAY. High-dose biotin (hair/nail supplements, 5-10 mg) can make TSH read falsely LOW and free T4 falsely HIGH -- mimicking hyperthyroidism on paper. Stop biotin 48-72 hours before the draw.

Ingredients with evidence in our library

• Seleniumsolid -- The best-evidenced nutrient on thyroid function in our library -- 18 rows here and 31 on thyroid antibodies, 17 of those human. The deiodinase enzymes that convert T4 to active T3 are selenoproteins, and glutathione peroxidase protects the gland from the peroxide it must generate to make hormone. Selenium repletion lowers TPO antibodies in multiple trials. (18 studies in our library, 11 in people)
• Iodinemixed -- The substrate hormone is literally built from -- but this is the clearest U-shaped nutrient in the whole panel. Too little causes hypothyroidism; too much also causes it, and can trigger autoimmunity in susceptible people. Do not supplement iodine on symptoms alone. (22 studies in our library, 8 in people)
• Zincsolid -- Studied alongside selenium in subclinical hypothyroidism with mechanistic and clinical evidence; required for deiodinase activity and for the receptor that reads the hormone. (9 studies in our library, 5 in people)
• Ironsolid -- Thyroid peroxidase is a haem enzyme -- without iron it cannot build hormone. Assessed in our library alongside ferritin and thyroid profile directly. (3 studies in our library, 2 in people)
• Vitamin Demerging -- Treatment moved thyroid function and autoimmunity markers together in our library's rows; status is consistently lower in autoimmune thyroid disease. (6 studies in our library, 3 in people)
• Myo-inositol with seleniumemerging -- Compared head-to-head against selenium alone in Hashimoto's with subclinical hypothyroidism -- the combination outperformed selenium alone on TSH. (4 studies in our library, 2 in people)
• Ashwagandhaemerging -- Appears in a systematic review of randomised herbal trials in hypothyroidism. Note the direction: it RAISES thyroid output, which makes it the wrong herb for anyone with a low TSH or on replacement. (2 studies in our library, 2 in people)
• Magnesiumemerging -- Severely low serum magnesium associated with positive anti-thyroglobulin antibodies -- an association, and a reason to check rather than a demonstrated lever. (1 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Magnesium is required by the enzymes that convert vitamin D to its active form, so magnesium shortfall can leave someone unresponsive to supplementation -- a common and fixable reason a dose does not move the number.
• Vitamin K2 directs the calcium that vitamin D helps absorb toward bone rather than soft tissue. The two are a pair, and supplementing D hard without K2 is the more common imbalance.
• Adequate fat is needed for absorption; vitamin D is fat-soluble and a very low-fat meal reduces uptake.

Exposures

• Obesity sequesters vitamin D in adipose tissue, so the same dose produces a smaller serum rise -- not a toxin, but the most common reason a level stays low despite supplementation.

Gut

• Fat malabsorption of any cause lowers vitamin D status, and coeliac or inflammatory bowel conditions are among the more common explanations for a stubbornly low level.

Detox capacity

• The liver performs the first hydroxylation to 25-OH vitamin D -- which is exactly what this test measures -- and the kidney performs the second. Significant impairment of either changes what the number means.

How it cascades

• Low magnesium -> impaired activation -> supplementation fails to raise the level -> the dose gets pushed higher instead of the cofactor being corrected.
• Vitamin D raises calcium absorption -> without adequate K2 that calcium has no clear destination -> which is the mechanistic argument for pairing them. Stated as mechanism, not as a proven outcome.

What people often feel when it runs high

• Excess comes from supplements, essentially never from sun.
• Nausea, vomiting, poor appetite, constipation, excessive thirst and urination.
• Confusion and weakness.
• ⚠️ THE DANGER OF TOXICITY IS HYPERCALCAEMIA AND KIDNEY STONES, not the vitamin D itself. If very high doses are being used, calcium needs measuring too.

What people often feel when it runs low

• Fatigue -- our library holds an explicit study of 25(OH)D and fatigue severity in adults.
• Aching bones and muscles, particularly the shins, hips and lower back; tenderness when pressed.
• Muscle weakness, especially getting out of a chair or climbing stairs; increased falls in older adults.
• Low mood, and mood that clearly worsens through winter.
• Getting ill often, and recovering slowly.
• Hair loss.
• Slow wound healing.
• ⚠️ MOST DEFICIENCY IS SILENT. Symptoms appear late, which is why this is one of the highest-value measurements in the panel -- deficiency is extremely common, cheap to test and cheap to fix.

Patterns it travels in

• VITAMIN D LOW + MAGNESIUM LOW -- the enzymes that convert vitamin D to its active form are magnesium-dependent. A vitamin D level that will not rise on a good dose is a magnesium question, and this is the commonest reason supplementation underperforms. 10 rows in our library pair them.
• VITAMIN D + CALCIUM + PTH read as one. Vitamin D low with PTH high means the body is pulling calcium from bone to compensate -- the finding that most justifies acting. 71 rows carry both vitamin D and calcium tags.
• VITAMIN D LOW + HS-CRP HIGH runs both ways: deficiency permits more inflammatory signalling, and inflammation lowers measured 25(OH)D. A single low reading during illness may not represent the person's baseline.
• VITAMIN D LOW + TPO ANTIBODIES POSITIVE -- a consistent association, with treatment moving function and autoimmunity markers together in our rows.
• VITAMIN D LOW + OMEGA-3 INDEX LOW is the commonest deficiency pair in this panel, and VITAL tested both in one trial.
• VITAMIN D + VITAMIN K2 -- D increases calcium absorption, K2 governs where that calcium is deposited. Mechanistically compelling and short on hard outcome trials; our library holds 4 rows. Say mechanism, not proof.
• ⚠️ VITAMIN D IS FAT-SOLUBLE -- taken without fat in the meal, much of the dose is wasted. And obesity sequesters it in adipose tissue, so a higher dose is often needed for the same blood level.

Ingredients with evidence in our library

• Vitamin D3 (cholecalciferol), taken with a fat-containing mealsolid -- 795 rows, 345 human -- the second-largest human evidence base in this library. D3 raises and maintains 25(OH)D more effectively than D2. Fat in the meal materially changes how much is absorbed. (795 studies in our library, 345 in people)
• Magnesiumsolid -- 10 rows, 5 human, and a far larger mechanistic literature. Required for both hydroxylation steps that activate vitamin D -- correcting magnesium is often what unblocks a stubborn vitamin D level. (10 studies in our library, 5 in people)
• Vitamin K2 (MK-4 / MK-7)emerging -- Directs the calcium that vitamin D makes available into bone rather than soft tissue. Our library holds phosphocalcic metabolism work covering D, K2 and nattokinase together. Mechanism is strong; outcome evidence is emerging. (4 studies in our library, 2 in people)
• Calciumsolid -- 71 rows, 22 human, including the fracture and falls prevention literature where the two were tested together rather than separately. (71 studies in our library, 22 in people)
• Sunlight -- the free onesolid -- Skin synthesis remains the dominant natural source. It is limited by latitude, season, skin tone, age, glass and sunscreen -- above roughly 37 degrees latitude, winter sun is too weak to make any regardless of exposure time. Worth saying plainly rather than implying a supplement is the only option. (819 studies in our library, 345 in people)
• Boronemerging -- Slows the clearance of active vitamin D, extending its half-life. A small and genuinely under-studied finding -- 2 rows in our library, and stated as the thin signal it is. (2 studies in our library, 0 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• "Bones, stones, groans and psychic moans" -- the old teaching phrase, and still the best summary: bone pain, kidney stones, abdominal pain and constipation, low mood and confusion.
• Excessive thirst and frequent urination.
• Fatigue and muscle weakness.
• ⚠️ A RAISED SERUM CALCIUM IS NEVER A NUTRITION FINDING AND MUST NOT BE TREATED AS ONE. It is a parathyroid, kidney or malignancy question, and it needs a doctor -- always with PTH measured alongside it. This is one of the few results in the whole panel where 'take a supplement' is the wrong response in every case.

What people often feel when it runs low

• Tingling around the mouth and in the fingers and toes.
• Muscle cramps and twitching, and in more marked cases carpopedal spasm.
• Irritability, anxiety, low mood, fatigue.
• ⚠️ CHECK MAGNESIUM AND ALBUMIN BEFORE TREATING A LOW CALCIUM. Magnesium deficiency causes a calcium that will not correct with calcium, because PTH cannot be released or heard without it. And roughly half of serum calcium is bound to albumin -- a low albumin lowers total calcium with no deficiency at all, which is why ionised or albumin-corrected calcium is the number that means something.

Patterns it travels in

• SERUM CALCIUM IS A POOR MEASURE OF CALCIUM INTAKE AND A GOOD MEASURE OF CALCIUM CONTROL. It is held in a narrow band by PTH and vitamin D at the expense of the skeleton, so someone can have a badly inadequate intake and a perfectly normal serum calcium for decades. If the question is bone, this is not the test.
• CALCIUM + PTH TOGETHER, ALWAYS. Calcium high with PTH high says parathyroid; calcium high with PTH suppressed says something else is driving it. Neither is readable from calcium alone.
• CALCIUM LOW + VITAMIN D LOW + PTH HIGH is secondary hyperparathyroidism -- the body cannibalising bone to hold serum calcium up. Our library carries 56 rows pairing vitamin D with calcium status for exactly this reason.
• CALCIUM LOW + MAGNESIUM LOW -- correct the magnesium first or the calcium will not move. 17 rows in our data pair the two.
• CALCIUM + ALBUMIN. Always read the corrected value; low albumin fakes a low calcium.
• CALCIUM + VITAMIN K2 + VITAMIN D as an intake question rather than a serum one -- D increases absorption, K2 directs where it is deposited. Supplementing D and calcium without K2 is the arrangement most often criticised, and the criticism is mechanistic rather than trial-proven.
• CALCIUM HIGH + EGFR FALLING + PHOSPHORUS HIGH belongs to kidney medicine and needs a clinician.

Ingredients with evidence in our library

• Vitamin Dsolid -- The dominant partner across our calcium rows (56, 22 human) -- it governs how much dietary calcium is absorbed at all. Correcting vitamin D usually does more for calcium status than adding calcium does. (56 studies in our library, 22 in people)
• Magnesiumsolid -- Required for PTH release and for tissue response to it -- a low calcium that will not correct is a magnesium problem until proven otherwise. (17 studies in our library, 3 in people)
• Vitamin K2 (MK-4/MK-7)emerging -- Carboxylates osteocalcin and matrix Gla protein -- the proteins that put calcium into bone and keep it out of arteries. Mechanistically strong, and the human outcome evidence is thinner than the mechanism suggests. Stated as emerging, not solid. (4 studies in our library, 2 in people)
• Dietary calcium in food formmixed -- Across 64 tagged rows including systematic-review evidence on osteoporosis. Food sources come with the cofactors; isolated high-dose calcium supplements have a more contested cardiovascular record, which is worth saying plainly. (64 studies in our library, 16 in people)
• Phosphorus balanceemerging -- Appears on 18 of our calcium rows. A very high phosphorus intake -- overwhelmingly from cola and processed food phosphate additives -- works against calcium, and is a subtraction worth making before an addition. (18 studies in our library, 2 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Copper is required for ceruloplasmin, which loads iron onto transferrin -- without adequate copper, iron cannot be mobilised properly no matter how much is taken. This is the single most missed cofactor in iron work.
• Vitamin C substantially increases absorption of non-heme iron taken with it; vitamin A status also affects iron mobilisation from stores.
• Riboflavin and B12 shortfall both impair the red cell production that iron feeds into.

Exposures

• Lead competes with iron for the same intestinal transporter -- and iron shortfall increases lead absorption, so the two aggravate each other in both directions.

Gut

• Iron is absorbed in the duodenum, so coeliac disease, low stomach acid and H. pylori all reduce uptake. A non-responding iron level is a gut question before it is a dose question.
• Inflammation anywhere raises hepcidin, which locks iron inside storage cells -- producing low serum iron with normal or high ferritin. That pattern is inflammation, not deficiency, and iron will not fix it.

Detox capacity

• Ferritin is an acute-phase reactant, so it rises with inflammation independently of iron stores. A normal ferritin does not rule out iron shortfall when CRP is up.

How it cascades

• Low ferritin with normal serum iron -> stores are empty while the circulating number still looks fine -> symptoms arrive before the standard panel flags anything.
• Inflammation -> hepcidin rises -> iron is sequestered -> low serum iron, high ferritin, and supplementing iron makes nothing better. Read iron beside hs-CRP or the picture inverts.

What people often feel when it runs high

• Often SILENT for years, which is what makes iron overload dangerous.
• Fatigue and joint pain, classically in the first two knuckles.
• A bronze or grey skin tint.
• Abdominal pain, and liver enzymes drifting up.
• Reduced libido, erectile difficulty, cycles stopping.
• ⚠️ IRON IS ONE OF THE FEW NUTRIENTS WHERE SUPPLEMENTING WITHOUT TESTING CAN DO SERIOUS AND IRREVERSIBLE HARM. The body has no route to excrete a surplus. Haemochromatosis is common (roughly 1 in 200 of northern European ancestry) and often only found when the liver is already involved. Never supplement iron on symptoms alone.

What people often feel when it runs low

• Fatigue that rest does not fix -- and it appears at LOW FERRITIN, long before haemoglobin falls or anaemia exists. This is why 'my blood count was normal' does not settle the question.
• Breathlessness on stairs or mild exertion; a racing heart on standing.
• Restless legs at night -- one of the most specific and most-missed signs of low ferritin.
• Hair shedding, three to six months after the iron fell rather than at the time.
• Brittle, spooned or ridged nails.
• Cold hands and feet.
• Brain fog, poor concentration, low mood.
• Pica -- craving ice, or non-food substances.
• Headaches, dizziness, pale skin and pale inner eyelids.
• Reduced exercise capacity and slow recovery.

Patterns it travels in

• FERRITIN LOW + HS-CRP HIGH is the single most misread combination in this entire panel. Ferritin is an acute-phase protein and RISES with inflammation, so a person can be genuinely iron-deficient with a ferritin that reads normal or high. Always read ferritin against hs-CRP -- and when inflammation is present, transferrin saturation and soluble transferrin receptor tell the truth that ferritin will not.
• FERRITIN LOW + TRANSFERRIN SATURATION LOW + TIBC HIGH is unambiguous iron deficiency. TIBC rising is the body making more transport in search of iron.
• FERRITIN HIGH + SATURATION HIGH (over ~45%) is the overload pattern and needs investigating, not ignoring. FERRITIN HIGH + SATURATION NORMAL OR LOW is usually inflammation, liver disease or alcohol -- a completely different meaning from the same high number.
• IRON LOW + B12/FOLATE LOW TOGETHER -- the MCV can read perfectly normal because one raises it and the other lowers it. A normal MCV does not exclude either when both are present.
• FERRITIN LOW + TSH HIGH -- thyroid peroxidase is a haem enzyme. Iron deficiency both causes thyroid symptoms and blunts the response to thyroid replacement, and our library carries this pairing directly.
• FERRITIN LOW + COELIAC, or + heavy periods, or + PPIs, or + a plant-based diet, or -- in any man or postmenopausal woman -- GI BLOOD LOSS UNTIL PROVEN OTHERWISE. That last one is the reason unexplained iron deficiency is a doctor's question and not a supplement's.
• FERRITIN LOW + HBA1C HIGH -- iron deficiency falsely RAISES HbA1c. Correcting the iron lowers the HbA1c with no change in glucose.

Ingredients with evidence in our library

• Vitamin C, taken with the ironsolid -- 100 rows, 23 human -- including ascorbic acid as an adjunct for anaemia in erythropoietin-treated patients. Ascorbate reduces ferric to ferrous iron at the gut lining and can multiply absorption of plant-source iron several-fold. It is the cheapest and most reliable lever on this marker, and it is a timing instruction rather than a purchase. (100 studies in our library, 23 in people)
• Iron bisglycinate, or alternate-day dosingsolid -- 1,527 rows, 371 human. A dose raises hepcidin for roughly 24 hours, which BLOCKS the next dose -- so alternate-day single doses absorb better than daily split doses and cause fewer gut side effects. One of the clearest cases where how you take it beats how much you take. (1527 studies in our library, 371 in people)
• Haem iron from meat, fish and liversolid -- Absorbed by a different pathway entirely, largely immune to phytate and polyphenol inhibition, and several times better absorbed than plant iron. (1527 studies in our library, 371 in people)
• Vitamin A and beta-caroteneemerging -- Mobilise iron from stores and improve absorption -- which is why iron deficiency that resists iron sometimes turns out to be a vitamin A problem. (110 studies in our library, 45 in people)
• Coppersolid -- 238 rows, 40 human. Iron cannot be loaded onto transferrin without the copper enzymes ceruloplasmin and hephaestin. Copper deficiency produces an anaemia that looks exactly like iron deficiency and does not respond to iron -- and the commonest cause of copper deficiency is high-dose zinc. (238 studies in our library, 40 in people)
• ⚠️ Tea, coffee, calcium and phytate, as subtractionssolid -- Tannins and phytate can cut non-haem iron absorption by more than half. Separating tea and coffee from iron-containing meals by an hour is free and frequently does more than a supplement. (2486 studies in our library, 1350 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Choline shortfall -- choline is required to package fat into VLDL and export it from the liver. Without enough, fat accumulates in hepatocytes and enzymes leak; controlled depletion studies in adults raise ALT and reverse it on repletion.
• Protein and amino-acid shortfall -- ALT and AST are themselves enzymes of amino-acid metabolism, so an under-fed liver can show deceptively LOW values. A low ALT is not automatically a healthy one.
• Vitamin B6 shortfall -- ALT and AST both require pyridoxal-5-phosphate as a cofactor, so B6 depletion can suppress measured activity independently of liver health. This is an assay-level effect, not a liver improving.

Exposures

• Alcohol -- classically raises AST more than ALT, and the ratio is often more informative than either number.
• PFAS -- the C8 Health Project (47,092 adults) and pooled NHANES data both associate serum PFOA and PFOS with higher ALT. See the PFAS marker.
• Medications and supplements metabolised hepatically, including some botanicals -- a rise here asks what was started recently, not only what was eaten.

Gut

• A compromised gut barrier lets endotoxin reach the liver through the portal vein, and the liver's immune response to that is a recognised driver of hepatic inflammation. This is the mechanism behind the gut-liver axis.

Detox capacity

• These enzymes are the liver's damage signal, not its detox capacity. Phase I/II throughput is better read from GGT and from what the liver is being asked to conjugate.

How it cascades

• Gut barrier loss -> endotoxin to the portal vein -> hepatic inflammation -> ALT rises. The useful question then is the gut, not the liver.
• Excess fructose or alcohol -> de novo lipogenesis -> hepatic fat -> enzyme leak. ALT is often the first ENZYME to move in metabolic dysfunction, well before glucose does.
• READ ALT WITH TRIGLYCERIDES -- they are two readouts of the same process and triglycerides frequently move FIRST. The liver makes fat from excess fructose and alcohol, packages it into VLDL, and ships it out as circulating triglycerides; what it cannot export stays behind as hepatic fat, and only then do enzymes leak. So a raised triglyceride with a normal ALT can be the earlier warning, not the milder one. A dietary fructose restriction trial measured exactly this chain -- liver fat and de novo lipogenesis both fell together.
• The reverse direction matters too: hepatic fat drives hepatic insulin resistance, which raises VLDL output, which raises triglycerides further. It is a loop, not a one-way arrow, which is why the two numbers tend to rise and fall together.
• Muscle injury or hard training raises AST (and CK) without any liver involvement at all -- check the timing of the last heavy session before reading a lone AST rise as hepatic.

What people often feel when it runs high

• Usually NOTHING. The liver has no pain fibres in its tissue, and enzymes can run raised for years silently -- which is the entire argument for measuring them.
• Where symptoms exist: a dull ache or fullness under the right ribs, fatigue, and nausea.
• Fatigue disproportionate to activity is the commonest complaint that turns out to have a raised ALT behind it.
• Itching without a rash, and yellowing of the eyes, belong to the more advanced picture and need a doctor rather than a supplement.
• ⚠️ ALT ABOVE AST usually points at fatty liver; AST ABOVE ALT (roughly 2:1 or more) points at alcohol. The RATIO carries information the individual numbers do not.
• ⚠️ A HARD WORKOUT RAISES AST AND CK FOR DAYS -- muscle contains AST too. Do not draw these within 48-72 hours of heavy training and then interpret them as liver.

What people often feel when it runs low

• A low ALT is not usually a concern in itself, but a persistently very low ALT can reflect vitamin B6 deficiency -- ALT requires pyridoxal-5-phosphate to function, so the assay under-reads without it. Also seen in frailty and low muscle mass.

Patterns it travels in

• READ ALT WITH TRIGLYCERIDES -- they are two readouts of the same process, and TRIGLYCERIDES FREQUENTLY MOVE FIRST. Our library holds the fructose-restriction work in which liver fat and de novo lipogenesis fell together (25 rows, 12 human-typed), and 66 rows pairing triglycerides with liver fat. If triglycerides are up and ALT is normal, the process has already started.
• ALT HIGH + TRIGLYCERIDES HIGH + FASTING INSULIN HIGH + WAIST UP is metabolic fatty liver, and it is by far the commonest cause of a raised ALT. The lever is metabolic -- fructose and alcohol out, weight down -- not a liver supplement.
• AST:ALT RATIO ABOVE 2 + GGT HIGH + MCV HIGH is the alcohol pattern, and it is worth recognising before anything else is tried.
• ALT HIGH + FERRITIN HIGH + TRANSFERRIN SATURATION HIGH -- consider iron overload rather than assuming inflammation. Our library holds ferritin and liver steatosis in children with metabolic clustering explicitly. This one changes what should happen next.
• ALT HIGH + PLATELETS FALLING + ALBUMIN FALLING is the combination that means the liver's synthetic function is affected, not just irritated. That is a clinician's finding, not a nutrition one.
• ALT HIGH + NEW MEDICATION OR SUPPLEMENT -- always ask. Statins, paracetamol, and a number of botanicals raise it, and the answer is often simply stopping something.
• ALT NORMAL DOES NOT EXCLUDE FATTY LIVER. Imaging finds it in plenty of people whose enzymes are perfectly normal.

Ingredients with evidence in our library

• Cutting fructose -- the best-evidenced lever, and it is a subtractionsolid -- Our library holds dietary fructose restriction measured directly on liver fat and de novo lipogenesis, with 12 human-typed rows. Liquid fructose -- sugar-sweetened drinks and juice -- is the concentrated source. Nothing purchasable in this library outperforms it. (25 studies in our library, 12 in people)
• Cholinesolid -- 21 rows. Choline is required to package fat into VLDL and export it from the liver; without enough, fat accumulates regardless of how little is eaten. One of the commonest inadequate intakes in Western diets, and eggs and liver are the dense sources. (21 studies in our library, 5 in people)
• Probiotics, synbiotics and prebiotic fibresolid -- 31 rows across the probiotic and prebiotic tags, measured directly on liver enzymes in non-alcoholic fatty liver disease. The gut-liver axis is a real route: the portal vein delivers gut endotoxin to the liver first. (31 studies in our library, 6 in people)
• Artichoke leaf extractemerging -- 12 rows, 5 human -- reduced steatosis and decreased liver size in pre-bariatric patients. One of the better-evidenced botanicals on this specific marker in our library. (12 studies in our library, 5 in people)
• Glutathione precursors (NAC, glycine, sulfur amino acids)emerging -- 50 rows across the glutathione and NAC tags -- but note the honesty: almost none are human-typed on this marker. Per the cross-reference spec's antioxidant rule, the framing is supplying what the liver builds glutathione FROM, not supplying glutathione. (50 studies in our library, 0 in people)
• Vitamin Emixed -- 13 rows, 9 human. Has the strongest trial record of any supplement in non-alcoholic steatohepatitis specifically, though at doses that carry their own debate. (13 studies in our library, 9 in people)
• Vitamin B6emerging -- 10 rows. Not a treatment -- a reading correction. ALT requires P5P as its cofactor, so B6 deficiency makes the enzyme under-report and can hide a liver problem. (10 studies in our library, 3 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Albumin depends on protein intake AND on the liver's capacity to synthesise it, so a low value is ambiguous by design -- it can mean too little protein, an inflamed liver, or losses through gut or kidney.
• Alkaline phosphatase is a zinc metalloenzyme -- it will not work without zinc, so an unexplained LOW ALP is one of the more useful practical hints of zinc shortfall.
• Magnesium is also required for ALP activity, so low-normal ALP is worth reading alongside magnesium status rather than alone.

Exposures

• Anything driving cholestasis raises ALP and, with it, bilirubin -- the pattern of which of these move together matters more than any single value.

Gut

• Intestinal alkaline phosphatase is a distinct isoenzyme produced in the gut, where it detoxifies endotoxin at the barrier. A total ALP is a mixture of sources, and that is one reason a single number can mislead.
• Protein-losing conditions in the gut lower albumin without any liver problem at all.

Detox capacity

• Bilirubin is the end product of haem breakdown and is conjugated by the liver before excretion, so it reads conjugation and flow. It is also a genuine endogenous antioxidant -- mildly raised unconjugated bilirubin, as in Gilbert's, is not the same finding as a raised conjugated fraction.

How it cascades

• Inflammation anywhere -> the liver shifts synthesis toward acute-phase proteins -> albumin falls. Read a low albumin alongside an inflammatory marker before reading it as nutrition.
• Zinc shortfall -> ALP falls -> and the same shortfall shows up in taste, immune function and skin. One low enzyme, several visible consequences.
• Cholestasis -> ALP and conjugated bilirubin rise together, while ALT and AST may stay near normal -- the pattern separates a flow problem from a damage problem.

What people often feel when it runs high

• HIGH BILIRUBIN: yellowing of the eyes, and dark urine. Most commonly Gilbert's syndrome -- a harmless inherited variant affecting several percent of people, in which bilirubin rises with fasting, illness or stress and nothing is wrong.
• HIGH ALP: bone pain or liver/bile symptoms. Which one it is depends entirely on GGT -- ALP up with GGT up is liver or bile; ALP up with GGT normal is bone. In children and teenagers a high ALP is normal growth.
• HIGH GLOBULIN with low albumin (a reversed A/G ratio) reflects chronic inflammation or immune activation and deserves a clinician's look.

What people often feel when it runs low

• LOW ALBUMIN: swelling of ankles and feet, puffiness around the eyes, fatigue, poor wound healing, muscle loss.
• Low albumin is one of the strongest general predictors of poor outcomes there is -- it reflects protein intake, liver synthesis, kidney loss and inflammation all at once.
• LOW ALP can reflect zinc or magnesium deficiency -- alkaline phosphatase is a zinc-dependent enzyme, so a persistently low ALP is a genuine and widely-missed zinc signal. 108 of our rows on this marker carry the zinc tag, the largest single association.
• LOW BILIRUBIN carries no symptoms; it is mildly associated with lower antioxidant capacity, since bilirubin is itself an antioxidant.

Patterns it travels in

• ALBUMIN CHANGES THE MEANING OF OTHER RESULTS -- read it first. Roughly half of serum calcium and most serum zinc are albumin-bound, so a low albumin fakes a low calcium and a low zinc. This is the single most useful thing albumin does on a panel.
• ALBUMIN LOW + HS-CRP HIGH is the acute-phase response seen from both directions -- CRP is a positive acute-phase protein, albumin a negative one. Together they suggest a sustained process.
• ALP LOW + ZINC LOW -- alkaline phosphatase is a zinc metalloenzyme. A low ALP is one of the few genuinely useful functional zinc signals available on a standard panel, and it costs nothing extra.
• ALP HIGH + GGT HIGH = liver/bile. ALP HIGH + GGT NORMAL = bone. This single pairing resolves the commonest ambiguity in a liver panel.
• ALP HIGH + VITAMIN D LOW + PTH HIGH + CALCIUM LOW-NORMAL is the bone-turnover picture of secondary hyperparathyroidism.
• BILIRUBIN HIGH + EVERYTHING ELSE NORMAL + rises with fasting = Gilbert's. Common, benign, and a frequent cause of unnecessary alarm.
• ALBUMIN LOW + PROTEINURIA points at the kidney losing it rather than the liver failing to make it -- check urinalysis before assuming liver.

Ingredients with evidence in our library

• Zincsolid -- 108 rows, 22 human -- the largest association on this marker group, driven by ALP's absolute dependence on zinc as a cofactor. Repletion raises a low ALP. This is a mover in the most literal sense: no zinc, no enzyme. (108 studies in our library, 22 in people)
• Adequate dietary proteinsolid -- Albumin is made from amino acids. In older adults especially, a low albumin is frequently an intake and absorption question before it is a disease question -- and it is the one intervention that addresses the marker directly. (475 studies in our library, 147 in people)
• Magnesiumemerging -- A cofactor alongside zinc for alkaline phosphatase activity. (17 studies in our library, 3 in people)
• Vitamin Dsolid -- 9 rows, 5 human. Governs the bone-turnover side of ALP -- deficiency raises ALP through secondary hyperparathyroidism, and correcting it brings ALP down. (9 studies in our library, 5 in people)
• Selenium and copperemerging -- 38 rows combined. Our library holds serum albumin mediating associations between heavy metals and systemic inflammation indices -- albumin is part of how the body buffers metal exposure, which is why it appears in the toxicity work. (38 studies in our library, 11 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• HIGH CREATININE / LOW eGFR: usually SILENT until filtration is well down -- which is exactly why it is measured rather than felt.
• Later: swelling in ankles and around the eyes, foamy urine, fatigue, poor appetite, itching, night urination, high blood pressure.
• ⚠️ CREATININE IS PRODUCED BY MUSCLE, so a muscular person reads 'worse' and a frail person reads 'better' at the same true filtration rate. Cystatin C does not depend on muscle mass and is the better test where body composition is unusual.
• ⚠️ CREATINE SUPPLEMENTATION RAISES CREATININE WITHOUT HARMING THE KIDNEY -- it is a measurement artefact, not damage. Our library carries a systematic review of renal safety in adolescents. So does a big steak the night before, and so does dehydration.

What people often feel when it runs low

• A low creatinine usually reflects low muscle mass rather than excellent kidneys, and in older adults it can hide meaningfully reduced filtration.

Patterns it travels in

• eGFR + CYSTATIN C TOGETHER where the answer matters. When creatinine-based and cystatin-based estimates disagree, the truth is usually between them -- and the disagreement itself is information about muscle mass.
• eGFR FALLING + URINE ALBUMIN-TO-CREATININE RATIO RAISED is the pair that matters. ALBUMINURIA APPEARS FIRST, often years before eGFR moves, and a urine ACR is cheap. Ordering eGFR without it is the commonest gap in kidney screening.
• eGFR FALLING + URIC ACID HIGH -- the kidney clears about two-thirds of uric acid, so urate can be the earlier signal.
• eGFR FALLING + POTASSIUM HIGH + PHOSPHORUS HIGH + PTH HIGH is the mineral picture of reduced filtration and belongs to a clinician.
• ⚠️ eGFR CHANGES WHAT IS SAFE TO SUPPLEMENT. Magnesium and potassium accumulate when filtration is reduced, and both become genuinely dangerous. Check eGFR before recommending either at dose -- this is the marker with the most direct bearing on whether our own advice is safe.
• eGFR FALLING + BLOOD PRESSURE HIGH + GLUCOSE HIGH is the commonest cause combination by a wide margin, and all three are the same conversation.
• BUN HIGH + CREATININE NORMAL usually means dehydration or a high protein intake rather than a kidney problem.

Ingredients with evidence in our library

• Sodium reductionsolid -- 31 rows, 17 human -- the largest signal on this marker in our library. Lowering sodium lowers glomerular pressure and albuminuria, and it is the intervention with the most consistent evidence behind it. (31 studies in our library, 17 in people)
• Dietary potassium (from food, and only with a known eGFR)mixed -- 22 rows -- urinary and dietary potassium measured against microvascular complications. ⚠️ The direction reverses in reduced filtration: potassium becomes a risk rather than a benefit. This is the clearest example in the whole panel of an intervention whose safety depends on another marker. (22 studies in our library, 5 in people)
• Magnesiummixed -- A randomised controlled trial in our library on magnesium supplementation and vascular calcification in chronic kidney disease. Same caution: accumulation risk when filtration is reduced. (8 studies in our library, 2 in people)
• Probiotics (the gut-kidney axis)emerging -- 8 rows -- probiotics with AST-120 on renal function. Gut bacteria generate the uraemic toxins indoxyl sulfate and p-cresyl sulfate that the kidney must then clear, so changing the gut changes the load. (8 studies in our library, 2 in people)
• Vitamin B12emerging -- 8 rows -- effect on glycaemic control, albuminuria and peripheral neuropathy measured together. (8 studies in our library, 3 in people)
• Vitamin Demerging -- An umbrella review in our library on efficacy and safety in diabetic kidney disease. (9 studies in our library, 5 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• HIGH POTASSIUM: palpitations, muscle weakness, and in severe cases dangerous heart rhythms. ⚠️ THIS IS ONE OF THE FEW GENUINELY URGENT RESULTS ON A ROUTINE PANEL. Reduced kidney function, ACE inhibitors and potassium supplements are the usual causes -- and a haemolysed sample is a very common false positive worth excluding before anyone panics.
• HIGH SODIUM: thirst, dry mouth, confusion -- almost always dehydration rather than salt intake.

What people often feel when it runs low

• LOW SODIUM: headache, nausea, confusion, fatigue, muscle cramps. Severe drops cause seizures. Commonest causes are medication (diuretics, SSRIs), and -- increasingly -- drinking large volumes of plain water during endurance events.
• LOW POTASSIUM: muscle weakness and cramps, constipation, palpitations and skipped beats, fatigue.
• ⚠️ A LOW POTASSIUM THAT WILL NOT CORRECT IS A MAGNESIUM PROBLEM. Magnesium deficiency opens a renal channel that dumps potassium as fast as it is replaced -- 17 rows in our library pair the two, and it is the single most useful electrolyte rule there is.

Patterns it travels in

• POTASSIUM LOW + MAGNESIUM LOW -- correct magnesium first or the potassium will not hold. The rule worth teaching before any other.
• SODIUM LOW + high water intake + endurance exercise is exercise-associated hyponatraemia, and it is caused by drinking TOO MUCH plain water, not too little. Our library holds sweat electrolyte profiles during daily activity (83 potassium rows, 96 sodium rows) -- sweat carries both, and replacing only the water is what causes the problem.
• SODIUM-TO-POTASSIUM RATIO IS MORE INFORMATIVE THAN SODIUM ALONE. Most Western diets are high sodium and low potassium; the ratio captures that in one number, and our hs-CRP rows carry it too.
• POTASSIUM HIGH + eGFR LOW is the combination to take seriously and act on quickly.
• CHLORIDE + BICARBONATE together describe acid-base status; low bicarbonate with a normal anion gap points at bicarbonate loss.
• GLUCOSE HIGH + ELECTROLYTES DISORDERED -- our library holds the impact of fasting plasma glucose on electrolyte imbalance directly. Glycosuria drags sodium, potassium and magnesium out with it.

Ingredients with evidence in our library

• Magnesium -- the permissive mineralsolid -- 17 rows, 7 human, including genetic tubular disorders where the mechanism is unambiguous. Nothing else on this panel corrects reliably while magnesium is low. (17 studies in our library, 7 in people)
• Dietary potassium (vegetables, fruit, legumes, potatoes)solid -- 83 rows, 19 human. Food potassium comes with the bicarbonate precursors that supplements lack, and it is not subject to the dose limits placed on potassium supplements. ⚠️ Only with a known eGFR. (83 studies in our library, 19 in people)
• Sodium, replaced deliberately during heavy sweatingsolid -- 96 rows, 37 human. Our library measures sweat electrolyte profiles directly -- sweat is not plain water, and replacing it with plain water is what produces exercise-associated hyponatraemia. The correct framing is replacing what was lost, not restricting salt universally. (96 studies in our library, 37 in people)
• Chloride, and bicarbonate for acid loademerging -- 17 rows on chloride; our library also holds sodium bicarbonate therapy in metabolic acidosis and bicarbonate with cholecalciferol and protein together. (17 studies in our library, 3 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Iron shortfall makes cells SMALL (low MCV); B12 or folate shortfall makes them LARGE (high MCV). Cell size is the first fork in the road, and it points at different nutrients.
• Copper shortfall causes an anaemia that looks like iron deficiency and does not respond to iron -- an uncommon cause that is nearly always missed because copper is rarely measured.
• Vitamin B6 is required for haem synthesis itself.

Exposures

• Lead interferes with haem synthesis directly and is a classic cause of anaemia with basophilic stippling.

Gut

• Almost every nutritional anaemia is an absorption story before it is an intake story -- coeliac disease, low stomach acid and H. pylori all reach the red cell indices.

Detox capacity

• Red cell turnover produces bilirubin, so accelerated breakdown raises unconjugated bilirubin without any liver problem.

How it cascades

• A normal MCV can hide combined deficiency: iron shrinking cells and B12 enlarging them can average out to a normal-looking size. RDW -- the spread of cell sizes -- catches what the average hides, which is why it is worth reading.
• Small cells -> check ferritin, and read it beside CRP because inflammation inflates it. Large cells -> check B12 with methylmalonic acid, and folate.

What people often feel when it runs high

• HIGH HAEMOGLOBIN/HAEMATOCRIT: headaches, flushing, itching after a hot shower, dizziness.
• Commonest causes are dehydration (a false rise), smoking, sleep apnoea, altitude and testosterone therapy -- all worth asking about before anything rarer.

What people often feel when it runs low

• LOW HAEMOGLOBIN: fatigue, breathlessness on stairs, palpitations, pale skin and pale inner eyelids, headaches, cold hands and feet, poor concentration.
• LOW MCV (small cells) points at iron deficiency, or at thalassaemia trait if iron studies are normal.
• HIGH MCV (large cells) points at B12 or folate deficiency, alcohol, or an underactive thyroid.
• ⚠️ SYMPTOMS OF IRON DEFICIENCY START AT LOW FERRITIN, NOT AT LOW HAEMOGLOBIN. A perfectly normal CBC does not exclude iron deficiency, and 'your blood count is fine' is the sentence that sends people away still exhausted.

Patterns it travels in

• MCV IS THE MOST INFORMATIVE NUMBER ON THE CBC AND THE ONE MOST OFTEN IGNORED. Small = iron. Large = B12 or folate. It sorts the two commonest deficiencies in one number.
• ⚠️ THE TRAP: IRON DEFICIENCY AND B12 DEFICIENCY TOGETHER GIVE A NORMAL MCV, because one lowers it and the other raises it. A normal MCV excludes neither when both are present -- and both together is common in the same people (coeliac disease, gastric surgery, plant-based diets, autoimmune gastritis).
• MCV LOW + FERRITIN LOW + RDW HIGH is iron deficiency in progress. RDW rises early because new small cells sit alongside older normal ones -- it is often the first thing to move.
• MCV LOW + FERRITIN NORMAL + RDW NORMAL suggests thalassaemia trait rather than iron deficiency, and giving iron on that misreading does harm.
• MCV HIGH + MMA HIGH = B12. MCV HIGH + MMA NORMAL + HOMOCYSTEINE HIGH = folate. MCV HIGH + GGT HIGH = alcohol.
• HAEMOGLOBIN LOW + HS-CRP HIGH + FERRITIN NORMAL-OR-HIGH is anaemia of inflammation, not iron deficiency, and iron will not fix it. Our library names this pattern directly (anaemia, micronutrient deficiency and elevated inflammation biomarkers in women).
• HAEMOGLOBIN LOW + COPPER LOW -- copper deficiency causes an anaemia that looks exactly like iron deficiency and does not respond to iron. Its commonest cause is long-term high-dose zinc.
• HAEMATOCRIT HIGH + a morning headache + snoring -- ask about sleep apnoea before treating the blood.

Ingredients with evidence in our library

• Iron, with vitamin C, dosed alternate-daysolid -- 196 rows, 101 human -- the dominant signal. Vitamin C multiplies non-haem absorption; alternate-day dosing beats daily because a dose raises hepcidin for about 24 hours and blocks the next one. (196 studies in our library, 101 in people)
• Vitamin B12solid -- 55 rows, 16 human. Corrects a high MCV -- and must be established before folate is pushed, or the blood picture improves while nerve damage continues. (55 studies in our library, 16 in people)
• Folate (B9)solid -- 36 rows, 10 human, including erythrocyte folate measured directly rather than serum folate -- red cell folate reflects months of status rather than this week's intake. (36 studies in our library, 10 in people)
• Riboflavin (B2)emerging -- 16 rows, 7 human, including a paper finding riboflavin deficiency HIGHLY PREVALENT in females and children across both high and low/middle income countries. B2 is required to mobilise iron from ferritin -- so riboflavin deficiency produces an iron-resistant anaemia. This is the quietest genuinely useful finding in the whole CBC group. (16 studies in our library, 7 in people)
• Vitamin Asolid -- 20 rows, 16 human -- one of the highest human proportions in this library. Vitamin A mobilises iron from stores; deficiency produces anaemia that iron alone does not correct. (20 studies in our library, 16 in people)
• Coppersolid -- 17 rows. Required to load iron onto transferrin. Without it, iron cannot be transported no matter how much is given. (17 studies in our library, 4 in people)
• Zincsolid -- 43 rows, 24 human -- measured alongside anaemia and inflammation biomarkers together. (43 studies in our library, 24 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Usually an active infection -- fever, feeling unwell, a specific site that hurts.
• Neutrophils raised: bacterial infection, inflammation, tissue injury, or simply steroids or acute stress (a genuine and often-forgotten cause).
• Lymphocytes raised: viral infection more often than bacterial.
• Eosinophils raised: allergy, asthma, drug reactions, and parasites.
• ⚠️ A PERSISTENTLY HIGH COUNT WITH NO INFECTION NEEDS A DOCTOR, not a supplement.

What people often feel when it runs low

• Frequent or lingering infections; mouth ulcers; slow recovery.
• Low lymphocytes travel with chronic stress and high cortisol, with poor nutrition, and with zinc deficiency.
• ⚠️ A LOW NEUTROPHIL COUNT CAN BE A NORMAL ETHNIC VARIANT (benign ethnic neutropenia, common in people of African ancestry) and is not always a problem. It can also be a drug effect -- always ask what someone is taking.

Patterns it travels in

• THE NEUTROPHIL-TO-LYMPHOCYTE RATIO CARRIES MORE INFORMATION THAN EITHER COUNT ALONE, and it is free -- it is already on every CBC. A rising ratio with a normal total WBC tracks systemic inflammatory burden and stress, and reads as normal on any automated flag.
• NLR HIGH + HS-CRP HIGH is inflammation confirmed two ways, one of them at no extra cost.
• LYMPHOCYTES LOW + CORTISOL HIGH -- cortisol redistributes lymphocytes out of circulation. A low lymphocyte count in someone under sustained stress is often that, not immune deficiency.
• EOSINOPHILS HIGH + IgE HIGH is the allergic picture; EOSINOPHILS HIGH with travel history is a parasite question.
• WBC LOW + MCV HIGH + PLATELETS LOW together suggests a marrow or B12 problem rather than three separate findings, and needs a clinician.
• WBC NORMAL DOES NOT MEAN NO INFLAMMATION -- it is a count of cells, not a measure of activation.

Ingredients with evidence in our library

• Zincsolid -- 17 rows, 9 human -- including a randomised trial of zinc supplementation on inflammation and gut integrity markers. Zinc is required for lymphocyte development and function, and deficiency shrinks the thymus. (17 studies in our library, 9 in people)
• Vitamin Csolid -- 14 rows, 10 human. Neutrophils actively concentrate vitamin C to millimolar levels -- far above plasma -- to run the oxidative burst and then clear themselves. This is one of the most specific cell-level vitamin C roles there is. (14 studies in our library, 10 in people)
• aiE10 (dialysable leukocyte extract / transfer factors)emerging -- 11 rows in our library, including a randomised clinical trial of oral dialysable leukocyte extracts as immunomodulators. This is the science's name for it -- searching the product name returns nothing, because no researcher has ever written a trademark in a paper. (11 studies in our library, 1 in people)
• Beta-carotene and watercress-type crucifersemerging -- 7 rows, 4 human -- watercress supplementation reduced lymphocyte DNA damage and altered blood antioxidant status. A measured cellular endpoint rather than a general antioxidant claim. (7 studies in our library, 4 in people)
• Probioticsemerging -- 5 rows -- impact on lymphocyte population and function measured in marathon runners, a population where immune suppression after heavy exertion is well documented. (5 studies in our library, 2 in people)
• Seleniumemerging -- 6 rows -- immune function studied with zinc- or selenium-supplemented support. (6 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• USUALLY NOTHING -- and that is the entire argument for measuring it. ApoB counts particles, and particle number produces no sensation at any level. Someone can sit at 130 mg/dL for twenty years and feel completely well.
• Where symptoms do appear they belong to what travels WITH a high ApoB, not to ApoB itself -- the central weight gain, the afternoon crash after carbohydrate, the rising blood pressure of the insulin-resistant pattern.
• Visible lipid deposits -- tendon xanthomas, a corneal arcus before about age 45 -- are rare but meaningful, and they point at inherited familial hypercholesterolaemia rather than at diet.

What people often feel when it runs low

• Also silent. Genuinely low ApoB is usually good news; very low readings alongside low albumin, low total cholesterol and unintended weight loss point at absorption or liver capacity, and belong to a clinician's assessment rather than a supplement plan.

Patterns it travels in

• APOB HIGH + TRIGLYCERIDES HIGH + HDL LOW is the metabolic pattern, not the familial one. The particles are small, cholesterol-poor and numerous, so LDL-C can read 'normal' while ApoB is clearly raised. Reading LDL-C alone is what misses this person entirely.
• APOB HIGH + LDL-C EQUALLY HIGH + TRIGLYCERIDES NORMAL reads the other way -- fewer, larger, cholesterol-rich particles, more often inherited. It is the combination that justifies asking about family history and about Lp(a).
• APOB + LP(a) TOGETHER, ONCE. Lp(a) carries its own ApoB molecule and is set genetically, so a stubborn ApoB that will not respond to diet is sometimes an Lp(a) hiding inside it. Lp(a) needs measuring only once in a lifetime -- ApoB is the one that gets repeated.
• APOB HIGH + HS-CRP HIGH is the combination that changes the conversation. Particle number and arterial inflammation are separate processes and each is worth knowing; together they describe both the cargo and the condition of the road.
• APOB HIGH + TSH HIGH is the one worth ruling out before anything is bought. An underactive thyroid slows LDL-receptor clearance and raises ApoB, and correcting the thyroid corrects the lipids -- treating it as a diet problem wastes months.

Ingredients with evidence in our library

• Beta-glucan (oat/barley)solid -- Lowers LDL-cholesterol, non-HDL-cholesterol and ApoB together -- the meta-analytic endpoint set most directly relevant to particle number. Viscous fibre binds bile acids, so the liver must clear more particles to rebuild them. (11 studies in our library, 7 in people)
• Psyllium (Plantago ovata)solid -- Same bile-acid mechanism, measured explicitly against 'alternative lipid targets' including ApoB rather than LDL-C alone. (2 studies in our library, 2 in people)
• Beta-sitosterol / plant sterolssolid -- Competes with cholesterol for intestinal absorption; roughly 5-15% lower LDL-C and ApoB at about 2 g/day. (6 studies in our library, 3 in people)
• Bile-salt-hydrolase-active probioticsemerging -- Deconjugate bile salts in the gut so they are excreted rather than reabsorbed, which imposes the same demand on the liver as fibre does. A genuinely different route to the same endpoint. (1 studies in our library, 1 in people)
• Omega-3 (EPA/DHA)mixed -- Lowers triglyceride-rich VLDL, which lowers ApoB modestly. Direction is inconsistent for particle number specifically, and high-dose fish oil raises LDL-C slightly in some people -- an honest mixed result, not a clean win. (44 studies in our library, 34 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Omega-3 shortfall, and a high omega-6 to omega-3 ratio, shift eicosanoid production toward the inflammatory side.
• Magnesium and vitamin D shortfall both associate with higher CRP in population data.
• Low antioxidant status raises oxidative stress, which feeds the same inflammatory signalling.

Exposures

• Heavy metals, air particulates and persistent organics all raise systemic inflammatory signalling -- CRP is where a diffuse exposure burden becomes a number.

Gut

• A compromised barrier lets endotoxin into circulation, and that is one of the best-characterised routes to a raised CRP with no obvious infection. When CRP is up and nothing hurts, the gut is worth looking at.

Detox capacity

• Inflammation and detoxification compete for the same resources -- glutathione especially -- so a sustained CRP raises the demand side of everything GGT reflects.

How it cascades

• Gut barrier loss -> endotoxin -> systemic inflammation -> CRP rises -> and the same inflammation raises hepcidin (iron locked away) and lowers albumin. One upstream cause, three markers moving.
• hs-CRP is nonspecific by design. Its value is as a yes/no on whether an inflammatory process is running -- it never says where.

What people often feel when it runs high

• Deep, unrefreshing fatigue -- searched as 'tired all the time blood tests normal' and 'why am i tired even after 8 hours sleep'. Inflammatory signalling is genuinely sedating; this is not deconditioning.
• Brain fog, slow word-finding, a sense of thinking through cotton wool.
• Aching that migrates and has no injury behind it -- stiffness that is worse in the morning and eases with movement.
• Low mood and anhedonia with no situational cause -- 'losing interest in everything but not depressed'. Inflammatory cytokines act directly on motivation circuitry.
• Poor recovery from ordinary exertion, and getting ill more easily than peers.
• ⚠️ A SINGLE HIGH READING USUALLY MEANS A COLD, NOT A CHRONIC STATE. Any infection, injury or hard training session in the preceding two weeks can push hs-CRP far above baseline. One value is close to uninterpretable -- repeat it when well before drawing any conclusion.

What people often feel when it runs low

• No symptoms. Low is the desirable direction.

Patterns it travels in

• HS-CRP HIGH + FERRITIN HIGH + IRON SATURATION LOW is the pattern most often misread in this whole panel. Ferritin is an acute-phase protein and rises with inflammation, so inflammation can make a genuinely iron-deficient person look iron-replete. Iron given on that misreading makes things worse. Always read ferritin against hs-CRP -- our own measurement shows iron tags appearing on 13 hs-CRP rows for exactly this reason.
• HS-CRP HIGH + ALBUMIN LOW is the same acute-phase response seen from both ends -- CRP is a positive acute-phase protein and albumin a negative one. Together they suggest a sustained process rather than a passing one.
• HS-CRP HIGH + VITAMIN D LOW is the commonest modifiable pair in the library on this marker (9 rows, 8 of them human), and it runs in both directions -- low vitamin D permits more inflammatory signalling, and inflammation lowers measured 25(OH)D.
• HS-CRP HIGH + HBA1C HIGH + TRIGLYCERIDES HIGH is metabolic inflammation, driven from adipose tissue and liver. The lever is metabolic, not anti-inflammatory supplementation.
• HS-CRP HIGH + NEUTROPHIL-TO-LYMPHOCYTE RATIO HIGH adds the immune shape of the response to its intensity.
• HS-CRP NORMAL DOES NOT MEAN NO INFLAMMATION. It is a liver-produced systemic signal; localised gut, joint or oral inflammation can be substantial with a normal hs-CRP.

Ingredients with evidence in our library

• Vitamin Dsolid -- The strongest and most human-weighted association on this marker in our library -- status tracks inversely with hs-CRP, and supplementation trials show reduced oxidative-stress and inflammatory parameters. Read causally with caution: inflammation itself lowers measured 25(OH)D. (9 studies in our library, 8 in people)
• Probiotics and synbioticssolid -- Lower circulating inflammatory biomarkers including hs-CRP -- the gut-barrier route the cross-reference spec predicts, and one of the few with human trial weight behind it here. (8 studies in our library, 7 in people)
• Saffron / crocinsolid -- Systematic review and meta-analysis on inflammation and oxidative stress specifically -- reduced inflammatory markers. Consistently one of the better-evidenced botanicals in this library. (5 studies in our library, 4 in people)
• Curcuminsolid -- Reduced oxidative-stress and inflammatory markers in human supplementation trials. (4 studies in our library, 4 in people)
• Zincsolid -- Meta-analysis of supplementation and immune factors in adults shows movement in inflammatory measures; zinc is also required for the antioxidant enzymes that restrain the response. (5 studies in our library, 4 in people)
• Vitamin Eemerging -- Improved biomarkers of intestinal inflammation alongside lipid changes -- again the gut-barrier route rather than a direct antioxidant effect on the marker. (5 studies in our library, 5 in people)
• Seleniumemerging -- Double-blind randomised trial evidence in an autoimmune population; selenium is the cofactor for glutathione peroxidase, which is upstream of the oxidative signalling that drives CRP. (3 studies in our library, 3 in people)
• Butyrate and the fibres that produce itemerging -- Oral synbiotics shifted gut microbiota and inflammatory biomarkers together. Butyrate is the fuel colonocytes use to maintain the barrier whose failure drives endotoxin-mediated inflammation. (3 studies in our library, 3 in people)
• Extra virgin olive oil (oleic acid + polyphenols)emerging -- Daily consumption moved biomarkers of inflammation and oxidation in human trials. (2 studies in our library, 2 in people)
• Boswellia serrataemerging -- Standardised extract attenuated exercise-induced inflammatory response over ten days -- a narrow, specific finding rather than a general anti-inflammatory claim. (2 studies in our library, 2 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Palpitations, tremor, heat intolerance, anxiety, weight loss, loose stools, poor sleep -- the overactive picture.

What people often feel when it runs low

• The hypothyroid picture even when TSH reads normal -- cold, flat, foggy, constipated, dry-skinned, losing hair.
• Low free T3 specifically tracks how someone FEELS better than TSH does, because T3 is the active hormone the tissues actually use.
• A distinct pattern in dieters and endurance athletes: free T3 falls first when energy availability drops. This is adaptive down-regulation, not thyroid disease, and it corrects with food rather than iodine.

Patterns it travels in

• FREE T4 NORMAL + FREE T3 LOW is a CONVERSION question, not a production one -- the gland is making the storage hormone but it is not being activated. Selenium, zinc and iron are the cofactors for that conversion, which is exactly what the library's 17 selenium rows and 5 zinc rows on this marker are about. Cortisol and inflammation both suppress the same step.
• FREE T3 LOW + REVERSE T3 HIGH + CORTISOL RAISED is the stress/illness pattern -- T4 is being routed to the inactive form deliberately.
• FREE T3 + FREE T4 BOTH LOW + TSH LOW points at the pituitary rather than the thyroid, and needs a clinician.
• IODINE + SELENIUM + ZINC MEASURED TOGETHER -- our library holds a study assessing exactly this joint impact on third-trimester thyroid function. They are not three separate questions; they are one.
• ⚠️ FREE T3 IS THE MARKER MOST OFTEN LEFT OFF A PANEL AND MOST OFTEN THE ONE THAT EXPLAINS THE SYMPTOMS.

Ingredients with evidence in our library

• Seleniumsolid -- The largest signal on this marker in our library. The deiodinases that convert storage T4 into active T3 are selenoproteins -- this is the single most mechanistically direct nutrient-to-marker link in the whole thyroid group. (17 studies in our library, 6 in people)
• Iodinemixed -- Substrate for hormone synthesis; measured jointly with selenium and zinc on third-trimester thyroid function. U-shaped -- more is not better. (13 studies in our library, 4 in people)
• Zincsolid -- Required for deiodinase activity and for thyroid hormone receptor binding; assessed jointly with iodine and selenium. (5 studies in our library, 3 in people)
• Ironsolid -- Studied directly on the relationship between iron deficiency and thyroid function in pregnancy -- haem-dependent thyroid peroxidase again. (1 studies in our library, 1 in people)
• Probiotics and synbioticsemerging -- Oral supplementation moved thyroid function in adults -- a meaningful fraction of T4-to-T3 conversion happens via gut bacterial sulfatases, which is the mechanism behind this otherwise surprising result. (2 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Often NONE for years. Antibodies commonly precede any change in TSH or in how someone feels by a long time -- which is the argument for measuring them early rather than waiting.
• Where symptoms exist they are the hypothyroid ones -- cold, fatigue, fog, hair thinning, heavy periods -- appearing while TSH still reads normal.
• A swollen or tender feeling at the front of the neck; difficulty swallowing tablets.
• Symptoms that swing between over- and under-active early on, as the gland releases stored hormone during flares.
• A personal or family history of other autoimmune conditions -- coeliac disease, type 1 diabetes, vitiligo, rheumatoid arthritis.

What people often feel when it runs low

• Negative antibodies are the desired result and carry no symptoms.

Patterns it travels in

• TPO ANTIBODIES POSITIVE + TSH NORMAL is the earliest actionable finding in the thyroid group -- autoimmunity is underway and function is still compensated. It is where selenium has its best evidence, and where nothing else needs doing yet.
• ANTIBODIES POSITIVE + FERRITIN LOW is common and bidirectional: autoimmune thyroid disease frequently coexists with autoimmune gastritis and coeliac disease, both of which impair iron absorption. Our library names this pair directly.
• ANTIBODIES POSITIVE + B12 LOW / MMA HIGH -- the same autoimmune gastritis mechanism removes intrinsic factor and with it B12 absorption. Worth checking rather than assuming.
• ANTIBODIES POSITIVE + VITAMIN D LOW is a consistent association in our rows, with treatment moving both function and autoimmunity markers.
• ANTIBODIES POSITIVE + MAGNESIUM SEVERELY LOW -- our library holds this specific association with positive anti-thyroglobulin antibodies.
• ⚠️ ANTIBODIES DO NOT NEED RE-MEASURING OFTEN. The titre fluctuates and chasing it wastes money; what matters is whether function is changing.

Ingredients with evidence in our library

• Seleniumsolid -- The strongest nutrient-to-autoimmunity signal in our entire library -- 31 rows, 17 human. Repletion lowers TPO antibody titres in multiple randomised trials. Mechanism is glutathione peroxidase protecting the gland from its own hydrogen peroxide. Two Brazil nuts a day supply the dose; more is not better, and selenium has a genuinely narrow window. (31 studies in our library, 17 in people)
• Myo-inositol with seleniumemerging -- Head-to-head against selenium alone in Hashimoto's with subclinical hypothyroidism; the combination did more. (4 studies in our library, 2 in people)
• Vitamin Demerging -- Treatment moved thyroid function and autoimmunity markers together in patients with autoimmune thyroid disease. (6 studies in our library, 3 in people)
• Ironsolid -- Iron and ferritin deficiency measured in women with hypothyroidism and chronic lymphocytic thyroiditis -- correcting it improves symptoms and the response to replacement. (7 studies in our library, 3 in people)
• Iodine -- the one to be careful withcontested -- Excess iodine can TRIGGER or worsen thyroid autoimmunity in susceptible people. In the presence of positive antibodies this is the nutrient to be cautious about rather than enthusiastic about, and that is the opposite of the usual supplement-aisle instinct. (13 studies in our library, 5 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• ⚠️ SELENIUM HAS ONE OF THE NARROWEST SAFE WINDOWS OF ANY MINERAL, and toxicity is a real risk from over-supplementing, not a theoretical one.
• A garlic smell on the breath with no garlic eaten -- the classic early sign.
• Brittle hair and nails, and hair loss -- the same symptom as deficiency, which is why guessing is a bad idea.
• Nausea, a metallic taste, skin rash, irritability.
• Excess selenium is also associated with raised fasting glucose and diabetes risk in trial data (SELECT).

What people often feel when it runs low

• Frequent infections and slow recovery from them -- selenium is required by the immune system's antioxidant defences.
• Thyroid symptoms: cold, fatigue, fog. Selenium deficiency shows up as thyroid dysfunction before almost anything else, because the gland holds the highest selenium concentration of any tissue.
• Muscle weakness and aching, particularly in the thighs.
• Hair thinning and white flecking of the nails.
• Low mood -- selenium status tracks with mood measures in several of our rows.
• Male fertility problems; selenium is required for sperm maturation.

Patterns it travels in

• SELENIUM + IODINE + ZINC + IRON is the thyroid quartet, and our library holds studies measuring their JOINT impact rather than treating them separately. Correcting one without the others frequently fails.
• SELENIUM LOW + IODINE LOW is the combination that must be corrected in the right order -- giving iodine to a selenium-deficient thyroid increases peroxide damage rather than helping. Selenium first.
• SELENIUM LOW + GLUTATHIONE LOW is one mechanism seen twice: glutathione peroxidase is a selenoenzyme, so glutathione capacity cannot be restored without selenium regardless of how much cysteine or NAC is supplied. 221 rows in our library carry both tags.
• SELENIUM LOW + TPO ANTIBODIES POSITIVE is where selenium has its strongest trial evidence in the entire library.
• SELENIUM + ZINC + COPPER read together -- these three compete and interact at absorption and in the antioxidant enzymes, and 262 zinc rows and 145 copper rows sit alongside selenium in our data for that reason.
• SELENIUM + MERCURY. Selenium binds mercury with extraordinary affinity, which both protects and depletes -- high mercury exposure lowers functional selenium status even when intake looks adequate.

Ingredients with evidence in our library

• Brazil nuts (the food, and the caution)solid -- The most concentrated ordinary food source by a wide margin -- one to two nuts a day typically achieves repletion. Content varies enormously with soil, so a handful daily is a genuine route to excess rather than a health habit. (1083 studies in our library, 259 in people)
• Selenomethionine (the food-form)solid -- The form most used in our library's human trials, including on thyroid antibodies and on mood and sexual function where vitamin E intake modulated the effect. (1083 studies in our library, 259 in people)
• Vitamin Esolid -- Modulates selenium's effect -- our library holds this as an explicit interaction, not an additive one. The two work in the same lipid-antioxidant system and each spares the other. (66 studies in our library, 13 in people)
• Zincsolid -- The most co-occurring mineral across selenium rows (262). They share transport and act together in oxidoreductive homeostasis; deficiency of both together is commoner than either alone. (262 studies in our library, 72 in people)
• Iodinesolid -- Read with selenium, always, and corrected after it. 99 rows carry both. (99 studies in our library, 18 in people)
• Glutathione and its precursorssolid -- Selenium is the limiting cofactor for glutathione peroxidase -- supporting the body's own antioxidant production rather than supplying the antioxidant directly, which is the framing the cross-reference spec requires. (221 studies in our library, 41 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Vitamin D and magnesium are mutually dependent -- the enzymes activating vitamin D need magnesium, and vitamin D increases magnesium absorption. Correcting one without the other is the usual reason neither improves.
• Vitamin B6 improves magnesium's entry into cells, which matters because serum magnesium is a poor guide to what is inside them.

Exposures

• Alcohol markedly increases urinary magnesium loss, as do some diuretics and proton pump inhibitors -- the drug history explains more low magnesium than diet does.

Gut

• Magnesium is absorbed along the small intestine and colon, so any malabsorption or chronic loose stool depletes it. High-dose oral magnesium that causes loose stool can be self-defeating.

Detox capacity

• Magnesium is a cofactor for glutathione synthesis, which puts it upstream of phase II conjugation capacity -- one of the quieter reasons it matters beyond muscle and sleep.

How it cascades

• SERUM MAGNESIUM IS THE WEAKNESS OF THIS TEST. Under 1% of body magnesium is in serum and the body defends that number by pulling from bone and cells, so a normal result is compatible with real depletion. Read it as a floor, not a status.
• Low magnesium -> impaired vitamin D activation -> vitamin D supplementation fails -> the dose is raised instead of the cofactor corrected.
• Low magnesium -> higher insulin resistance -> higher glucose -> more urinary magnesium loss. A self-reinforcing loop that shows up on the metabolic panel first.

What people often feel when it runs high

• Almost always caused by supplements plus reduced kidney function, not by food.
• Loose stools and abdominal cramping are the usual limit -- the gut sets its own ceiling on oral magnesium.
• ⚠️ IN KIDNEY IMPAIRMENT, MAGNESIUM ACCUMULATES AND BECOMES DANGEROUS -- low blood pressure, weakness, slowed heart rhythm. Check eGFR before supplementing at dose.

What people often feel when it runs low

• Muscle cramps, especially calves at night; eyelid twitching that goes on for days.
• Restless legs, and an urge to move the legs that is worse in the evening.
• Trouble falling asleep, and lighter, less restorative sleep -- 'racing thoughts at night can't sleep'.
• Anxiety and feeling permanently on edge -- 'why do i feel on edge for no reason'. Magnesium sits in the NMDA receptor's channel; without enough, that receptor is easier to excite.
• Palpitations and skipped beats.
• Headaches and migraine.
• Constipation.
• Fatigue -- every ATP molecule is biologically active only as a magnesium complex, so this is as literal an energy deficiency as exists.
• Painful periods, and worse premenstrual symptoms.
• ⚠️ SERUM MAGNESIUM IS A POOR TEST AND THE SYMPTOMS ARE OFTEN BETTER EVIDENCE. Under 1% of body magnesium is in serum and the body defends that number by pulling from bone and muscle, so serum stays normal well into deficiency. RBC magnesium is better; neither is great.

Patterns it travels in

• MAGNESIUM LOW + CALCIUM LOW that will not correct -- fix magnesium first. PTH cannot be released or heard without it, so calcium given alone fails. This is one of the highest-yield sequencing rules in the whole panel.
• MAGNESIUM LOW + POTASSIUM LOW that will not correct -- the same story. Magnesium deficiency opens a renal potassium channel and potassium is lost as fast as it is replaced. Our library carries 60 rows pairing the two.
• MAGNESIUM LOW + VITAMIN D LOW is a two-way dependency: the enzymes that hydroxylate vitamin D into its active form are magnesium-dependent, so vitamin D supplementation underperforms in magnesium deficiency -- and vitamin D supplementation increases magnesium demand. Correct them together.
• MAGNESIUM LOW + GLUCOSE HIGH is a self-reinforcing loop -- magnesium is required for insulin signalling, and glycosuria wastes magnesium in urine.
• MAGNESIUM LOW + TSH HIGH + HAIR LOSS appears directly in our rows (serum vitamin and mineral profiles in hypothyroidism-associated hair loss) alongside iron, zinc and calcium.
• MAGNESIUM LOW + ALCOHOL, or + PPIs, or + diuretics, or + high-dose zinc. All four deplete it, and three of them are things people take deliberately.
• MAGNESIUM + ZINC + COPPER together -- high-dose zinc lowers copper, and both compete with magnesium for absorption. 116 zinc rows and 57 copper rows sit alongside magnesium in our data.

Ingredients with evidence in our library

• Magnesium glycinate, malate or citrate (the absorbable forms)solid -- 775 rows, 241 human -- one of the largest bodies of human evidence in this library. Oxide is the cheapest and the least absorbed; it mostly works as a laxative. Form is the difference between a supplement working and passing through. (775 studies in our library, 241 in people)
• Vitamin D -- but in the right ordersolid -- 41 rows, 14 human. Vitamin D activation is magnesium-dependent, so magnesium repletion improves vitamin D response. Supplementing D at dose into a magnesium deficit increases the deficit. (41 studies in our library, 14 in people)
• Potassiumsolid -- 60 rows. The two travel together in electrolyte balance and neither corrects reliably alone. (60 studies in our library, 13 in people)
• Vitamin B6emerging -- Improves magnesium's entry into cells -- the classic pairing, and the reason many magnesium products include it. (17 studies in our library, 6 in people)
• Probiotics, via mineral absorptionemerging -- Our library holds probiotic-driven advancement in mineral absorption in the human gut, covering magnesium alongside calcium and selenium -- an indirect but real route. (30 studies in our library, 7 in people)
• Food: leafy greens, pumpkin seeds, cacao, legumes, mineral watersolid -- Our library holds a specific and easily-missed finding -- very low-mineral water is associated with worse cardiovascular measures and higher homocysteine. What is absent from drinking water counts as intake too. (828 studies in our library, 450 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Copper and zinc compete for the same intestinal transporter, so sustained high-dose zinc alone induces copper deficiency. This is the best-documented supplement-induced deficiency there is.
• Vitamin A and zinc depend on each other -- zinc is required for the retinol-binding protein that moves vitamin A out of the liver, so low zinc can look like low vitamin A.

Exposures

• Cadmium competes with zinc for binding sites and is a well-established antagonist; smoking is the dominant cadmium exposure in most people.
• Phytates in unsoaked grains and legumes bind zinc in the gut and meaningfully reduce absorption.

Gut

• Zinc is absorbed in the small intestine and is lost in diarrhoea; it is also required to maintain the gut barrier itself, so low zinc and a leaky barrier reinforce each other.

Detox capacity

• Zinc is a cofactor for metallothionein, the protein that binds and helps clear several heavy metals -- so zinc status sits directly upstream of how well someone handles metal exposure.

How it cascades

• Serum zinc is an imperfect marker for the same reason as magnesium -- it is tightly regulated and falls late. A low ALP is often the more practical hint, since ALP cannot work without zinc.
• High-dose zinc alone -> copper falls -> ceruloplasmin falls -> iron cannot be mobilised -> an anaemia that iron will not fix. Three markers moving from one supplement.

What people often feel when it runs high

• Nausea and metallic taste at high oral doses.
• ⚠️ THE REAL RISK OF EXCESS ZINC IS COPPER DEFICIENCY, and it is not rare. Sustained doses above about 40 mg/day induce a gut protein that blocks copper absorption -- causing anaemia that does not respond to iron, and in extreme cases irreversible nerve damage. 583 rows in our library carry both tags, which is why this is stated firmly. Long-term zinc without copper is a real mistake, not a theoretical one.

What people often feel when it runs low

• Frequent colds that last longer than everyone else's.
• Loss or dulling of taste and smell -- one of the most specific signs there is.
• Cuts and scrapes that heal slowly; acne that will not settle.
• White spots or lines on the nails; brittle nails; hair thinning.
• Skin that is dry, or eczema and rashes around the mouth and nose.
• Poor appetite.
• Low mood and poor concentration.
• Low testosterone and reduced libido in men; zinc is required for testosterone synthesis.
• Night vision that is worse than it was -- zinc is required to mobilise vitamin A.
• ⚠️ SERUM ZINC IS A WEAK TEST. It falls with any inflammation, with a recent meal, and later in the day. Draw it fasting, in the morning, and read it against hs-CRP -- a low zinc during inflammation may be redistribution rather than deficiency.

Patterns it travels in

• ZINC HIGH-DOSE + COPPER LOW is the single most important pairing on this marker. Never run high-dose zinc long-term without copper -- roughly 1 mg copper per 15 mg zinc is the usual ratio, and 583 rows in our library carry both.
• ZINC LOW + HS-CRP HIGH -- interpret with care. Inflammation redistributes zinc out of serum, so this may be a false low. Repeat when the inflammation has settled.
• ZINC LOW + ALBUMIN LOW -- most circulating zinc is albumin-bound, so a low albumin lowers measured zinc without a true deficiency.
• ZINC LOW + TSH HIGH + SELENIUM LOW is the thyroid quartet again; our library studies zinc and selenium together in subclinical hypothyroidism explicitly.
• ZINC LOW + IRON LOW + FERRITIN LOW travel together because they share dietary sources and the same absorption inhibitors -- phytate above all. 352 rows carry both tags. But take them at DIFFERENT times: iron and zinc compete for the same transporter.
• ZINC LOW + VITAMIN A LOW -- zinc is required to make retinol-binding protein, so vitamin A cannot be mobilised from the liver without it. A vitamin A deficiency that will not correct is often a zinc deficiency. 110 rows.
• ZINC LOW + GLUCOSE HIGH -- insulin is stored crystallised around zinc ions.
• ⚠️ VEGETARIAN AND VEGAN DIETS, PPIs, DIURETICS, HEAVY SWEATING AND ALCOHOL all lower zinc.

Ingredients with evidence in our library

• Zinc picolinate, citrate or bisglycinatesolid -- 2,123 rows, 444 human -- the largest single-ingredient evidence base in this library. Oxide absorbs poorly. Take away from food for absorption, or with food if it causes nausea, and never permanently at high dose without copper. (2123 studies in our library, 444 in people)
• Copper -- the mandatory partner, not an optional extrasolid -- 583 rows, 106 human. This is a safety pairing rather than a synergy: high-dose zinc induces metallothionein in the gut lining, which binds copper and prevents its absorption. The resulting anaemia looks like iron deficiency and does not respond to iron. (583 studies in our library, 106 in people)
• Seleniumsolid -- 261 rows, 72 human -- studied together throughout the thyroid and antioxidant literature; they act in the same oxidoreductive system. (261 studies in our library, 72 in people)
• Vitamin Asolid -- 110 rows, 45 human. Bidirectional: zinc is needed to transport vitamin A, and vitamin A status affects zinc utilisation. (110 studies in our library, 45 in people)
• Reducing phytate -- soaking, sprouting, fermenting, leaveningsolid -- The largest non-supplement lever, and the reason zinc deficiency concentrates in grain- and legume-heavy diets. Sourdough leavening degrades phytate; unleavened wholemeal is the worst case. A subtraction that works as well as an addition. (2298 studies in our library, 1096 in people)
• Oysters and red meat (the food answer)solid -- Oysters carry more zinc per gram than any other food by a wide margin, and animal-source zinc has none of the phytate problem. Our library carries desiccated oyster as a tagged ingredient. (2298 studies in our library, 1096 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• B12, folate and B6 are the three cofactors that clear homocysteine -- B12 and folate through remethylation, B6 through the transsulfuration route to cysteine. A raised homocysteine is usually a shortfall in one of them.
• Riboflavin is required by the MTHFR enzyme itself, which is why it matters more in people carrying reduced-function MTHFR variants.
• Choline and betaine provide an alternative remethylation route, so adequate choline lowers homocysteine independently of folate.

Exposures

• Heavy metals interfere with the methylation enzymes; alcohol depletes folate and B6 directly.

Gut

• B12 absorption needs intrinsic factor and adequate stomach acid, so atrophic gastritis, long-term acid suppression and metformin all raise homocysteine by that route.

Detox capacity

• The transsulfuration pathway turns homocysteine into cysteine and then glutathione -- so homocysteine sits at the junction between methylation and the body's main antioxidant supply. A rise can mean the pathway toward glutathione is blocked.

How it cascades

• This is a FUNCTIONAL marker: it reports whether the methylation cycle is running, which serum B12 often cannot. Methylmalonic acid answers the B12 half specifically.
• Low B12 -> remethylation stalls -> homocysteine rises AND methylmalonic acid rises -> the pair together separates B12 shortfall from folate shortfall, which homocysteine alone cannot.

What people often feel when it runs high

• Usually SILENT -- it is a biochemical finding, not a felt one, which is why it is a measurement worth making rather than a symptom to notice.
• Where symptoms exist they overlap the B-vitamin deficiencies driving it: fatigue, fog, low mood, tingling in hands and feet, poor memory.
• In pregnancy, recurrent miscarriage and neural tube risk -- which is why folate status is a preconception question rather than a pregnancy one.
• Migraine appears repeatedly in the MTHFR literature and remains an association rather than a demonstrated cause.

What people often feel when it runs low

• No symptoms. Very low values occasionally accompany high-dose supplementation and are not a concern in themselves.

Patterns it travels in

• HOMOCYSTEINE HIGH + MMA NORMAL = FOLATE or B6. HOMOCYSTEINE HIGH + MMA HIGH = B12. This is the cleanest either/or in the entire panel and it costs one extra test.
• HOMOCYSTEINE HIGH + MTHFR C677T -- and the finding in our own library that most people have never heard: RIBOFLAVIN (B2) is the cofactor the MTHFR enzyme uses, and riboflavin status modifies the blood-pressure effect of the C677T variant. For a TT genotype, B2 is a more specific answer than more folate, and it is almost never mentioned.
• HOMOCYSTEINE HIGH + KIDNEY FUNCTION FALLING -- the kidney clears homocysteine, so a raised value can be a filtration finding rather than a vitamin one. Check eGFR before buying B vitamins.
• HOMOCYSTEINE HIGH + TSH HIGH -- hypothyroidism raises homocysteine independently of B vitamins.
• HOMOCYSTEINE HIGH + VITAMIN D LOW appears in our rows via MTHFR polymorphism and vitamin D status in infertile women -- 8 rows, 7 of them human.
• ⚠️ LOWERING HOMOCYSTEINE WITH B VITAMINS HAS NOT RELIABLY LOWERED CARDIOVASCULAR EVENTS IN LARGE TRIALS, even though the association with risk is strong and consistent. It appears to be a marker of the underlying process more than a cause of it. Anyone selling B vitamins on a heart-attack claim is ahead of the evidence, and our own library is where that gets checked.
• ⚠️ THE B12-BEFORE-FOLATE RULE. Never push folate at dose without knowing B12 -- it corrects the blood picture while nerve damage continues.

Ingredients with evidence in our library

• Folate (B9), preferably as methylfolate where MTHFR variants are presentsolid -- The largest signal on this marker in our library -- 287 rows, 100 human, including a green-Mediterranean-diet trial measuring serum folate against genetic variation. Folate donates the methyl group that recycles homocysteine back to methionine. (287 studies in our library, 100 in people)
• Vitamin B12 (methylcobalamin)solid -- The enzyme that uses folate's methyl group is B12-dependent, so folate cannot work without it. Our library holds L-methylfolate plus methylcobalamin studied together on resistant hypertension associated with homocysteine. (188 studies in our library, 70 in people)
• Vitamin B6 (P5P)solid -- Runs the OTHER exit -- the transsulfuration route that converts homocysteine into cysteine and onward to glutathione. Where B12 and folate recycle it, B6 disposes of it, and a homocysteine that resists folate and B12 is often a B6 gap. (22 studies in our library, 8 in people)
• Riboflavin (B2)emerging -- The cofactor for MTHFR itself. Our library holds riboflavin, hypertension and MTHFR C677T in older adults -- the most specific and least-known intervention on this marker, and the one that matters most for the TT genotype. (7 studies in our library, 3 in people)
• Choline and betainesolid -- A parallel methyl-donation route independent of folate -- betaine can lower homocysteine when the folate pathway is limited. 11 rows here. (11 studies in our library, 5 in people)
• Creatinecontested -- Counterintuitive and worth knowing: creatine synthesis consumes a large share of the body's methyl groups, so supplying creatine can spare them. Our library's low-dose trial lowered plasma guanidinoacetate but NOT homocysteine -- a mechanism that did not deliver, reported as such rather than quietly dropped. (6 studies in our library, 2 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• HIGH MMA MEANS B12 IS FUNCTIONALLY LOW -- MMA piles up because the B12-dependent enzyme that clears it has stalled. It rises before serum B12 falls, which is the entire reason to measure it.
• Tingling, numbness or burning in the feet and hands, usually symmetrical and worse at night.
• Balance that is worse in the dark or with eyes closed -- the spinal cord columns B12 maintains are position-sense columns.
• Fatigue and breathlessness on exertion.
• Brain fog, poor concentration, memory slipping -- 'why am i so forgetful all of a sudden'.
• Low mood, irritability; in older adults, confusion that is mistaken for dementia.
• A sore, smooth, beefy-red tongue; mouth ulcers.
• Premature greying of hair -- our library holds a biochemical profile of exactly this.
• ⚠️ NERVE DAMAGE FROM B12 DEFICIENCY CAN BECOME PERMANENT. This is one of the few markers in the panel where delay costs something irreversible.

What people often feel when it runs low

• Normal MMA is the reassuring result and carries no symptoms.

Patterns it travels in

• MMA HIGH + SERUM B12 'NORMAL' is the whole point of the test. Serum B12 measures what is in the blood, including the large inactive fraction bound to haptocorrin; MMA measures whether the cells can actually use it. A B12 of 300 with a raised MMA is a deficient person with a normal-looking result.
• MMA HIGH + HOMOCYSTEINE HIGH = B12 (both pathways need it). MMA NORMAL + HOMOCYSTEINE HIGH = folate or B6, not B12. This single pair separates the two deficiencies cleanly and is the most useful discrimination in the whole B-vitamin group.
• MMA HIGH + MCV HIGH is the classic picture -- but MCV IS NORMAL IN UP TO A THIRD OF B12-DEFICIENT PEOPLE, and coexisting iron deficiency (which lowers MCV) hides it completely. Waiting for a large MCV is how the neurological damage gets missed.
• MMA HIGH + FOLATE HIGH is genuinely dangerous ground: high folate can correct the anaemia while the neurological damage continues unchecked. Never supplement folate at dose without knowing B12 status.
• MMA HIGH + TPO ANTIBODIES POSITIVE + FERRITIN LOW is autoimmune gastritis -- one stomach lining failure producing three findings. It is the pattern most worth recognising because it explains all of them at once.
• MMA HIGH + METFORMIN, or + LONG-TERM ACID SUPPRESSION (PPIs), or + a plant-based diet, or + age over 60, or + gastric surgery. These are the five commonest causes and four of them are things a form would have captured.

Ingredients with evidence in our library

• Vitamin B12 (methylcobalamin / hydroxocobalamin)solid -- By far the largest single nutrient-to-marker signal in our entire library -- 546 rows, 181 human. Repletion lowers MMA directly, because MMA rises only because B12 is missing. Absorption is the limiting question, not intake: where the cause is intrinsic-factor loss or gastric surgery, oral dosing may not be enough and injection is the honest answer. (546 studies in our library, 181 in people)
• Vitamin B9 (folate)solid -- Measured alongside B12 across 226 rows. Necessary in its own right -- and the one to be careful with, because folate alone can mask B12 deficiency while nerve damage progresses. (226 studies in our library, 79 in people)
• Vitamin B6solid -- Serum folate, B6 and B12 measured together in relation to cognitive outcomes -- the three move as a set rather than individually. (15 studies in our library, 5 in people)
• Ironsolid -- Co-occurs on 30 rows. Not a mover of MMA, but the thing most likely to be deficient alongside it and the reason MCV can look normal when both are. (30 studies in our library, 9 in people)
• Riboflavin (B2)emerging -- Required to regenerate the folate cycle; appears alongside B12 in our micronutrient assessment rows. The quietest of the B vitamins and a common gap in restricted diets. (8 studies in our library, 2 in people)
• ⚠️ Metformin, as a subtractionsolid -- Our library holds a paper on the synergistic and antagonistic interactions of essential micronutrients with biguanides. Metformin reduces B12 absorption over years -- so for anyone taking it, MMA is a marker to check periodically rather than once. (22 studies in our library, 5 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Very high intakes: easier bruising, longer bleeding from small cuts, and a fishy aftertaste or reflux.
• ⚠️ Above roughly 3 g/day of combined EPA/DHA, bleeding risk rises and LDL-C rises modestly in some people. More is not better here.

What people often feel when it runs low

• Dry, rough or bumpy skin on the backs of the arms; dry eyes; dry, brittle hair.
• Aching joints and slower recovery from training.
• Low mood and flat affect -- 'can t feel joy anymore'; the omega-3 and mood literature is large and genuinely mixed, and the honest framing is 'associated with', not 'treats'.
• Poor concentration and memory.
• ⚠️ A LOW OMEGA-3 INDEX IS COMMON AND SILENT. Most people in Western countries sit well below the 8% target and feel nothing specific -- which is why this is a measurement rather than a symptom question.

Patterns it travels in

• THE RATIO MATTERS MORE THAN EITHER NUMBER. A high omega-6 to omega-3 ratio with a low omega-3 index is the common Western pattern; our library holds the important corrective that lowering dietary linoleic acid ALONE does not lower arachidonic acid -- so the effective lever is adding EPA/DHA, not just removing seed oils. That is a genuinely counterintuitive finding and it is in our own data.
• OMEGA-3 INDEX LOW + TRIGLYCERIDES HIGH is the pair with the most consistent intervention evidence -- EPA/DHA lowers triglycerides reliably and dose-dependently, more reliably than it does anything else.
• OMEGA-3 INDEX LOW + HS-CRP HIGH -- the resolvins and protectins made from EPA and DHA are the body's active inflammation-RESOLVING signals, not merely the absence of inflammatory ones.
• OMEGA-3 INDEX LOW + VITAMIN D LOW is the commonest deficiency pair in this whole panel, and VITAL tested both together in one trial.
• OMEGA-3 + VITAMIN E. Polyunsaturated fats oxidise; vitamin E protects them. Our library pairs them on 6 rows, and it is the reason a good fish oil contains tocopherol.
• ARACHIDONIC ACID IS NOT SIMPLY THE VILLAIN. Our library holds work on restoring mitochondrial lipid homeostasis WITH arachidonic acid supplementation (95 rows carry the tag) -- it is a required structural fat, and the simple 'omega-6 bad' framing does not survive contact with the literature.

Ingredients with evidence in our library

• EPA and DHA (fish, fish oil, algal oil)solid -- The only thing that reliably raises the omega-3 index, because the index measures them. Dose and duration both matter -- the membrane takes about four months to re-equilibrate, so a re-test earlier than that measures nothing. (223 studies in our library, 86 in people)
• Krill oil / marine phospholipidsemerging -- Our library compares membrane incorporation across preparations directly -- phospholipid-bound forms incorporate somewhat more efficiently per gram than triglyceride forms, which matters for cost per unit of index moved rather than for whether it works. (13 studies in our library, 5 in people)
• ALA (flax, chia, walnut)mixed -- Measured head-to-head against EPA and DHA in our rows. Conversion of ALA to EPA is poor (single-digit percent) and to DHA poorer still, and it is worse in men. Useful food, weak lever for this specific marker -- say so rather than implying flax substitutes for fish. (6 studies in our library, 2 in people)
• Vitamin Esolid -- Protects the polyunsaturated fats being raised from oxidation; measured together with selenium, zinc and vitamin C in our intake rows. (6 studies in our library, 3 in people)
• GLA (evening primrose, borage)emerging -- A different arm of the omega-6 pathway with its own anti-inflammatory metabolite. Small literature here (4 rows) and stated as such. (4 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Anything that raises glutathione demand tends to raise GGT, because GGT sits on the cell membrane recycling glutathione. It is best read as a marker of oxidative and conjugation LOAD rather than of liver damage.
• Magnesium, selenium, and cysteine availability constrain glutathione synthesis and recycling -- selenium as the cofactor for glutathione peroxidase, cysteine as the rate-limiting amino acid.

Exposures

• Alcohol is the classic driver and the reason GGT is often read as an alcohol marker -- which under-uses it.
• Broad xenobiotic load -- solvents, pesticides and persistent organics raise conjugation demand and with it GGT.

Gut

• Endotoxin load from a compromised barrier adds to the same oxidative and conjugation demand that GGT reflects.

Detox capacity

• This is the closest routine marker to phase II conjugation capacity. A GGT that is high-normal alongside a clean ALT often means the liver is coping with a load rather than being injured by it -- a different conversation from a damage marker.

How it cascades

• Rising xenobiotic or oxidative load -> glutathione turnover rises -> GGT rises before ALT does. GGT often moves first, which is what makes it worth ordering.
• Sustained high GGT with normal ALT points at load; both rising together points at injury.
• GGT also tracks metabolic burden, not only toxic load -- it rises with hepatic fat and with triglycerides, which is why a GGT creeping up in someone who barely drinks is worth reading beside the lipid panel rather than dismissed.

What people often feel when it runs high

• Silent almost always -- GGT is a sensitive marker with no sensation attached.
• Where symptoms exist they belong to whatever is driving it: fatigue, right-sided fullness, poor sleep with alcohol use.
• ⚠️ GGT IS THE MOST SENSITIVE ROUTINE MARKER OF ALCOHOL INTAKE, and it is also raised by fatty liver, several medications, and simply carrying more weight. A raised GGT is not proof of drinking, and treating it as such is both wrong and insulting.

What people often feel when it runs low

• A low GGT is generally favourable. Very low values have been associated with lower glutathione turnover in some work -- an observation rather than a concern.

Patterns it travels in

• GGT IS THE OXIDATIVE-STRESS AND GLUTATHIONE MARKER HIDING IN A LIVER PANEL. The enzyme's actual job is recycling extracellular glutathione so its cysteine can be reused -- 18 of our 46 rows carry the glutathione tag, the highest proportion of any liver marker. A rising GGT within the normal range tracks oxidative burden and predicts metabolic outcomes years ahead.
• GGT ALSO TRACKS METABOLIC BURDEN, NOT ONLY TOXIC LOAD -- it rises with hepatic fat and with triglycerides. Our library holds liver function indicators as risk factors in paediatric metabolic dysfunction-associated fatty liver.
• GGT HIGH + AST:ALT ABOVE 2 + MCV HIGH is the alcohol pattern seen three ways.
• GGT HIGH + ALP HIGH points at the bile ducts rather than the liver cells. GGT is what separates a bone ALP from a liver ALP -- if ALP is up and GGT is normal, look at bone.
• GGT HIGH + FERRITIN HIGH + FASTING INSULIN HIGH is the metabolic-plus-oxidative cluster, and the combination most predictive of trajectory.
• ⚠️ A GGT IN THE UPPER HALF OF 'NORMAL' IS INFORMATION. Reference ranges are wide and this marker's risk gradient starts well inside them.

Ingredients with evidence in our library

• Reducing alcoholsolid -- The single largest and fastest lever, and it is free. GGT falls measurably within weeks of stopping -- one of the few markers that gives quick feedback. (46 studies in our library, 18 in people)
• Glutathione precursors -- cysteine, glycine, sulfuremerging -- 18 rows carry the glutathione tag, including work on cysteine and gamma-glutamylcysteine excretion in humans. GGT exists to recycle glutathione, so supplying its building blocks addresses the demand the enzyme is responding to. Frame as supporting the body's own production, per the spec's antioxidant rule. (20 studies in our library, 3 in people)
• Probiotics, synbiotics and prebiotic fibreemerging -- Measured on liver enzymes including GGT in non-alcoholic fatty liver disease. (3 studies in our library, 2 in people)
• ⚠️ The library is genuinely small here -- 46 rows, 18 human-typedemerging -- Stated plainly rather than padded. GGT was also the marker most damaged by a matcher bug found on 2026-09-04: a trailing word boundary stopped 'gamma-glutamyl' matching 'gamma-glutamyltransferase', undercounting it 5.75x. The count above is post-fix, and it is still a small literature. (46 studies in our library, 18 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Severe pain in the upper abdomen that bores through to the back, worse lying flat and eased leaning forward, with nausea and vomiting.
• ⚠️ THIS IS AN EMERGENCY PRESENTATION, NOT A WELLNESS FINDING. A markedly raised lipase with that pain needs urgent medical assessment, not a supplement plan. It is included here so the pattern is recognised, and for no other reason.
• Modest elevations are common and often mean nothing pancreatic at all -- reduced kidney clearance, salivary gland problems (amylase), and some medications all raise them.

What people often feel when it runs low

• Low pancreatic enzyme output shows as digestive symptoms rather than as a low blood number: pale, greasy, floating stools that are hard to flush, bloating and wind after fatty meals, unintended weight loss, and deficiency of the fat-soluble vitamins A, D, E and K.
• ⚠️ SERUM AMYLASE AND LIPASE ARE POOR TESTS OF DIGESTIVE CAPACITY. Faecal elastase measures whether the pancreas is actually delivering enzymes into the gut -- that is the test to ask about when the symptoms are digestive.

Patterns it travels in

• LIPASE IS MORE SPECIFIC THAN AMYLASE and stays raised longer. Amylase also comes from the salivary glands, so an isolated raised amylase with no pain is frequently salivary or renal rather than pancreatic.
• LIPASE HIGH + TRIGLYCERIDES VERY HIGH -- severe hypertriglyceridaemia is itself a cause of pancreatitis, which makes this pair a mechanism rather than a coincidence.
• LIPASE HIGH + GGT HIGH + ALP HIGH points at gallstones as the cause.
• LOW FAECAL ELASTASE + FAT-SOLUBLE VITAMIN DEFICIENCIES (A, D, E, K) + B12 LOW is exocrine pancreatic insufficiency -- one cause producing a scatter of deficiencies that look unrelated on a panel.
• ⚠️ MODEST ELEVATIONS + eGFR LOW -- reduced kidney clearance raises both enzymes without any pancreatic problem at all.

Ingredients with evidence in our library

• ⚠️ THE LIBRARY COUNT ON THIS MARKER IS MISLEADING, AND SAYING SO IS THE FINDING.contested -- 176 of 204 rows carry the 'digestive enzymes (protease/lipase/amylase)' tag -- but the top-ranked paper is on MONOACYLGLYCEROL LIPASE (MAGL) in substance use, which is an entirely different enzyme that happens to share the word 'lipase'. This is a homonym, not evidence. The honest position is that our library has very little on the pancreatic enzymes specifically, and none of it human-typed on this endpoint. (204 studies in our library, 113 in people)
• Pancreatic enzyme replacement, where insufficiency is actually demonstratedmixed -- A clinical intervention prescribed on a faecal elastase result, not a wellness supplement. Over-the-counter digestive enzymes are a different product at a different dose, and conflating the two is a claim we should not make. (176 studies in our library, 26 in people)
• The subtractions that matter more: alcohol and triglyceridessolid -- Alcohol and severe hypertriglyceridaemia are the two commonest modifiable causes of pancreatic injury. Neither is a supplement question, and both belong ahead of one in any honest ordering.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

Nutrient shortfalls

• Vitamin C is concentrated in the adrenal cortex and is consumed during cortisol production; B5 and magnesium are also required by the stress-response machinery.
• Chronic under-eating and low carbohydrate availability both raise cortisol -- the body treats energy shortage as a stressor.

Exposures

• Alcohol, poor sleep and caffeine late in the day all disturb the cortisol rhythm, which matters more than the absolute number.

Gut

• The gut-brain axis runs in both directions: microbiome disruption alters stress reactivity, and cortisol degrades the gut barrier. Each worsens the other.

Detox capacity

• Cortisol is cleared by the liver, so hepatic function affects exposure independently of how much is produced.

How it cascades

• A single cortisol reading is nearly meaningless without the time of day -- the RHYTHM is the finding. High at night and flat in the morning is a different problem from high overall.
• Sustained cortisol -> reduced T4-to-T3 conversion -> normal TSH with low functional thyroid activity; and -> gut barrier loss -> endotoxin -> raised CRP. One upstream driver, three downstream markers.
• Cortisol and DHEA-S come from the same precursor pool, so their ratio says more about sustained demand than either number alone.

What people often feel when it runs high

• "Wired but tired" -- exhausted all day, then alert the moment the head hits the pillow. The single most recognisable cortisol complaint.
• Waking at 3am, often with a racing heart or a jolt of anxiety -- 'why do i wake up at 3am with anxiety'.
• Anxiety and feeling permanently on edge; 'why do i feel on edge all the time'.
• Weight settling around the middle while arms and legs stay the same or thin.
• Sugar and salt cravings, especially late afternoon.
• Getting ill more often; wounds healing slowly.
• Poor sleep quality even with adequate hours; unrefreshing sleep.
• Blood pressure and blood glucose drifting up -- cortisol raises both by design.
• ⚠️ A SINGLE MORNING CORTISOL IS ALMOST UNINTERPRETABLE. The hormone follows a steep daily curve -- highest within 30-45 minutes of waking, lowest around midnight. The SHAPE of the curve is the finding, which is why four-point salivary or dried-urine collection tells you far more than one blood draw.

What people often feel when it runs low

• Profound fatigue that is worst in the morning, and improves slightly through the day -- the reverse of the usual pattern.
• Dizziness on standing; low blood pressure; salt craving.
• Nausea, poor appetite, unintended weight loss.
• Very poor stress tolerance -- ordinary demands feel overwhelming.
• ⚠️ GENUINELY LOW CORTISOL IS A MEDICAL CONDITION (adrenal insufficiency), not 'adrenal fatigue', and it is dangerous if missed. It needs a doctor and a proper stimulation test, never a supplement.

Patterns it travels in

• THE CURVE BEATS THE NUMBER. Four-point salivary or dried urine cortisol shows whether the morning rise is blunted, whether it stays high into the evening, or whether it is flat all day -- three completely different problems that one blood draw cannot distinguish.
• CORTISOL HIGH + DHEA-S LOW is the classic chronic-stress pattern -- both come from the same precursor, and sustained demand shifts the balance. The RATIO carries more information than either alone.
• CORTISOL HIGH + FASTING GLUCOSE HIGH + CENTRAL WEIGHT -- cortisol raises glucose deliberately. A glucose that misbehaves only during stressful periods, or runs high on waking, points here rather than at the pancreas.
• CORTISOL HIGH + FREE T3 LOW -- cortisol suppresses the T4-to-T3 conversion step. This is one of the commonest reasons someone with a normal TSH still has every hypothyroid symptom.
• CORTISOL HIGH + LYMPHOCYTES LOW -- cortisol redistributes lymphocytes out of circulation, so a low lymphocyte count in a stressed person is often that rather than immune deficiency.
• CORTISOL HIGH + MAGNESIUM LOW is a two-way loop: stress wastes magnesium in urine, and magnesium deficiency raises the stress response. Our library holds 34 rows pairing them, 16 human.
• CORTISOL HIGH + PROGESTERONE LOW -- both are made from pregnenolone, and sustained cortisol demand competes for the same precursor.
• ⚠️ CHECK BEFORE INTERPRETING: any corticosteroid (including inhaled and topical), the oral contraceptive pill (which raises cortisol-binding globulin and so total cortisol), night-shift work, and the time of the draw itself.

Ingredients with evidence in our library

• Ashwagandha (Withania somnifera)solid -- 19 rows, 15 human -- the highest human-trial proportion of any botanical in this library on this marker. Proprietary root extracts lowered cortisol and stress and anxiety measures in healthy adults. This is one of the few adaptogen claims that survives contact with the evidence. ⚠️ It raises thyroid output, so it is the wrong herb for anyone with a low TSH or on thyroid replacement. (19 studies in our library, 15 in people)
• Magnesium (with potassium)solid -- 34 rows, 16 human -- including supplementation measured on insomnia and sleep hormones directly. The loop runs both ways, which is why correcting it does more than the effect size alone suggests. (34 studies in our library, 16 in people)
• L-theaninesolid -- 10 rows, 8 human -- unusually high human proportion. Measured on sleep disorders and on stress in students during pharmacy practice. Raises alpha-wave activity without sedation. (10 studies in our library, 8 in people)
• Melatonin, and light timingsolid -- 36 rows, 13 human. Cortisol and melatonin are the two arms of one clock -- morning daylight and dark evenings set the cortisol curve more reliably than anything taken. The behavioural version of this is free. (36 studies in our library, 13 in people)
• Probiotics (psychobiotics)emerging -- 16 rows -- including heat-treated Lacticaseibacillus paracasei PS23 in long-COVID populations, plus gut microbiota modulation for insomnia. The gut-brain axis reaching the HPA axis is a real and increasingly well-mapped route. (16 studies in our library, 5 in people)
• GABA and tryptophanemerging -- 24 rows across both tags -- the raw materials for the calming and sleep-signalling side of the system rather than a sedative. (24 studies in our library, 5 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• In women: acne, oily skin, unwanted facial or body hair, scalp hair thinning, irregular cycles -- the PCOS-adjacent picture where adrenal androgens are the driver.
• ⚠️ A MARKEDLY RAISED DHEA-S NEEDS A DOCTOR to exclude an adrenal cause, not a supplement adjustment.
• Most commonly caused by taking DHEA itself, which is worth asking before investigating.

What people often feel when it runs low

• Low drive and blunted motivation -- 'no motivation to do anything but not depressed'.
• Reduced libido in both sexes.
• Poor recovery from exertion and from stress; feeling worn down rather than acutely stressed.
• Low mood and reduced sense of wellbeing.
• Thinning pubic and underarm hair in women; dry skin.
• ⚠️ DHEA-S FALLS NATURALLY AND STEEPLY WITH AGE -- by roughly 70-80% from its peak in the twenties. A 'low' result in a 60-year-old may be entirely age-appropriate, and an age-referenced range is essential.

Patterns it travels in

• CORTISOL:DHEA-S RATIO is the useful number, not either alone. Both come from pregnenolone; sustained stress shifts output toward cortisol and away from DHEA. A high ratio describes the chronic-stress state better than a cortisol on its own.
• DHEA-S LOW + FREE T3 LOW + LEPTIN LOW + CYCLES STOPPED is low energy availability -- restrictive eating or over-training. The correction is more food, and it is frequently mistaken for a hormone problem needing hormones.
• DHEA-S HIGH + TESTOSTERONE HIGH + LH:FSH RATIO RAISED + INSULIN HIGH is the PCOS pattern with an adrenal contribution.
• DHEA-S LOW + CORTISOL LOW + SODIUM LOW + POTASSIUM HIGH is a genuine adrenal insufficiency picture and needs urgent medical assessment.
• ⚠️ DO NOT SUPPLEMENT DHEA ON A LOW RESULT ALONE. It converts to both testosterone and oestrogen, the dose-response is unpredictable and individual, and in women it commonly produces acne and hair changes. It is a prescription-grade decision in most of the world for good reason.

Ingredients with evidence in our library

• Ashwagandha (Withania somnifera)emerging -- 3 rows, 2 human, on cortisol in stressed human subjects, plus a randomised double-blind placebo-controlled crossover examining hormonal effects including DHEA-S. The mechanism is the one that matters here: lowering sustained cortisol demand frees the shared pregnenolone precursor. (3 studies in our library, 2 in people)
• Reducing the cortisol demand -- sleep, training load, recoverysolid -- DHEA and cortisol are made from the same precursor, so the reliable route to a better cortisol:DHEA-S ratio is lowering the competing demand rather than supplying DHEA. Unglamorous, and it is what the physiology actually says. (1358 studies in our library, 586 in people)
• Adequate energy availabilityemerging -- DHEA-S falls with restrictive eating and over-training alongside low T3 and low leptin -- the low-energy-availability pattern. In that picture more food raises it and supplements do not. (71 studies in our library, 22 in people)
• ⚠️ Supplemental DHEA is not a wellness supplementcontested -- It converts to both testosterone and oestrogen with an unpredictable individual dose-response, commonly causes acne and hair changes in women, and is prescription-controlled in much of the world for good reason. A low age-adjusted result is not on its own a reason to take it. (71 studies in our library, 22 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• None, at any level, ever. Lp(a) is inherited, largely fixed after young adulthood, and produces no sensation -- which is why the great majority of people carrying a high level do not know.
• The signal is family history rather than symptom: early heart attack or stroke in a parent or sibling, especially before about 55 in men and 65 in women, and particularly where cholesterol looked unremarkable.

What people often feel when it runs low

• No recognised consequence.

Patterns it travels in

• LP(a) HIGH + APOB NORMAL is the classic miss. Standard lipid panels do not see Lp(a) at all, so risk that is entirely real reads as an entirely clean report.
• LP(a) HIGH + APOB HIGH is additive -- each contributes particles independently, and the practical response is to manage the modifiable one harder, because Lp(a) itself has no nutrition lever.
• MEASURE ONCE, NOT SERIALLY. About 80-90% of the level is genetic and stable for life. Repeat testing is one of the commonest wasted lab spends; the number's job is to recalibrate how aggressively everything else gets managed.

Ingredients with evidence in our library

• ⛔ Nothing in food or supplements meaningfully moves Lp(a) -- and our brain independently reached the same conclusion.solid -- `Labs/Nutrients/Foods-Per-Marker-Matrix.md` tags this [SOLID that diet has essentially no leverage here]. The level is roughly 80-90% genetically fixed and set for life after young adulthood. Measured across the approved library, only 15 rows name Lp(a) at all. Pharmacologic-dose niacin lowers it 20-25% in meta-analysis and the outcome trials (AIM-HIGH, HPS2-THRIVE) showed no cardiovascular benefit. (15 studies in our library, 8 in people)
• What to do instead -- and it is not nothingsolid -- The practical value of knowing a high Lp(a) is to manage everything modifiable more aggressively: ApoB, blood pressure, and not smoking. That is a real change in plan, which is why the test is worth doing once even though nothing moves the number itself. (659 studies in our library, 198 in people)
• ⚠️ Dietary trans fat raises itemerging -- One of the few dietary signals that exists at all here, and it runs in the harmful direction. Our library holds cis and trans fatty acids measured on serum Lp(a) in humans. (1 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Silent in itself. The small-dense pattern travels with the metabolic picture that does produce sensation -- the post-meal energy crash, the central weight that will not shift, the creeping blood pressure.

What people often feel when it runs low

• Silent. A large-buoyant-predominant pattern is generally the more favourable one.

Patterns it travels in

• SMALL DENSE LDL + TRIGLYCERIDES HIGH + HDL LOW is one physiological event with three names. Triglyceride-rich particles exchange lipid with LDL and HDL, leaving LDL small and dense and HDL depleted. If triglycerides and HDL already show the pattern, the subfraction test rarely changes what anyone does.
• SMALL DENSE LDL + FASTING INSULIN HIGH points upstream to insulin resistance as the driver -- which is where the intervention belongs, rather than at the lipid itself.
• ⚠️ THE TEST IS OFTEN REDUNDANT. Given ApoB plus triglycerides plus HDL, subfraction testing adds little and costs more. It earns its place mainly when ApoB and LDL-C disagree sharply and the reason matters.

Ingredients with evidence in our library

• Omega-3 (EPA/DHA)emerging -- The only intervention in this library measured directly on lipoprotein SUBFRACTIONS and particle size rather than on total LDL -- long-term fish oil shifted subfraction distribution and LDL size. Effect on total particle number stays modest. (3 studies in our library, 2 in people)
• Carbohydrate load, as the upstream leversolid -- Small-dense LDL is downstream of triglyceride-rich particles, so the levers that lower triglycerides -- reduced refined carbohydrate and alcohol, weight loss -- shift the pattern more reliably than anything aimed at LDL directly. The evidence for this sits under the triglyceride marker, not this one. (659 studies in our library, 198 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Hunger that does not switch off after an adequate meal -- the signal is present but not being heard.
• Weight that regains quickly after successful loss, out of proportion to what is being eaten.
• Low drive and cold intolerance during dieting -- falling leptin is one of the signals that tells the body to spend less energy.
• ⚠️ HIGH LEPTIN IS THE NORMAL FINDING IN STORED FAT, not a disorder in itself. It is interpretable only against body composition, which is why the number alone is close to meaningless.

What people often feel when it runs low

• Persistent hunger, cold hands and feet, low mood and stalled menstrual cycles -- the low-energy-availability pattern seen in restrictive eating and in over-training.
• In women, cycles that lengthen or stop. Leptin is one of the signals reproduction reads to decide whether there is enough energy available.

Patterns it travels in

• LEPTIN HIGH + FASTING INSULIN HIGH + TRIGLYCERIDES HIGH is the leptin-resistance picture -- plenty of signal, poor reception. Triglycerides themselves impair leptin transport across the blood-brain barrier, which is a rare case of a lipid marker directly explaining a hormone one.
• LEPTIN LOW + AMENORRHOEA + LOW T3 + LOW DHEA-S is energy deficiency, and it is the pattern most often mistaken for a thyroid problem. The correction is more food, not more supplementation.
• ⚠️ RARELY WORTH ORDERING. Leptin almost never changes what anyone does that body composition, insulin and triglycerides have not already said more cheaply. Its real use is confirming low energy availability in an athlete or a restrictive eater.

Ingredients with evidence in our library

• The library is genuinely thin here, and the honest answer is to say so.contested -- Measured across the whole approved library: 162 rows name leptin, but only 29 carry ingredient tags and almost none of those are human trials with leptin as the endpoint. This is one of the few markers where the shortage is real rather than a matching failure -- the same search that returns 18 human-typed zinc rows for glucose returns essentially nothing here. (162 studies in our library, 53 in people)
• Vitamin Demerging -- Supplementation moved leptin and interleukin-6 together in women post-intervention -- the only reasonably clean human signal on this marker in our library. (2 studies in our library, 2 in people)
• Sleep and energy availability, not a supplementsolid -- Leptin is set by fat mass, energy balance and sleep. Short sleep lowers leptin and raises ghrelin within days in controlled studies. Nothing in a bottle competes with that, and a page implying otherwise would be inventing evidence this library does not hold.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Joint pain and stiffness that is WORSE IN THE MORNING and eases with movement -- the opposite of mechanical wear, which worsens through the day. That single distinction is the most useful question there is here.
• Symmetrical small-joint swelling -- both hands, both wrists.
• Prolonged morning stiffness, over about 30-60 minutes.
• Fatigue that is disproportionate and unrefreshing.
• Dry eyes and dry mouth.
• Rashes, particularly across the cheeks or triggered by sun.
• Raynaud's -- fingers going white then blue in the cold.
• Unexplained low-grade fevers, hair loss, mouth ulcers.
• ⚠️ A POSITIVE ANA IS COMMON IN PEOPLE WITH NOTHING WRONG. Roughly 1 in 5 healthy adults tests positive at low titre, more in older women. On its own it means very little, and it has caused an enormous amount of unnecessary fear.

What people often feel when it runs low

• A negative result is the expected one and carries no symptoms.

Patterns it travels in

• ⚠️ NEVER ORDER THIS WITHOUT SYMPTOMS. A positive ANA in someone with no symptoms generates anxiety, more tests and no benefit. It belongs in a panel only when the morning-stiffness, symmetrical-swelling picture is actually present.
• ANA POSITIVE + HS-CRP HIGH + SYMPTOMS is a very different result from ANA positive alone -- inflammation confirms something is active.
• ANA POSITIVE + TPO ANTIBODIES POSITIVE -- autoimmunity clusters. Thyroid autoimmunity is the commonest, and finding one is a reason to check the other.
• AUTOIMMUNITY + FERRITIN LOW + B12 LOW is the coeliac / autoimmune gastritis pattern -- one gut lining problem producing several deficiencies, and worth testing for directly.
• RHEUMATOID FACTOR IS ALSO POSITIVE in hepatitis C, in chronic infections and in a fair share of healthy older people. Anti-CCP is far more specific and is the better test when the question is genuinely rheumatoid.

Ingredients with evidence in our library

• Vitamin D -- the VITAL result, which is a prevention signal, not a treatment oneemerging -- VITAL (25,871 participants) found vitamin D supplementation reduced INCIDENT autoimmune disease diagnoses by 22% over about 5.3 years. ⚠️ Read that precisely: it is population-level prevention. It is NOT evidence that vitamin D lowers an already-positive ANA titre in someone with established disease, and our brain's `Panels/Autoimmune.md` states that distinction explicitly. (25871 studies in our library, 25871 in people)
• A supervised fast followed by gluten-free vegan then lacto-vegetarian eatingsolid -- One of the very few dietary interventions in the whole Labs folder with a genuinely positive, replicated RCT in an established autoimmune disease -- significant improvement in tender and swollen joint counts, ESR and CRP, sustained to one year. The trial base remains modest and it requires supervision, but it is real and it is more than most supplements can show. (1 studies in our library, 1 in people)
• Omega-3 (EPA/DHA)emerging -- The signal is stronger in people genetically AT RISK for rheumatoid arthritis -- lower RF and anti-CCP positivity -- than in people with already-established disease, where the evidence is genuinely mixed. The direction of that difference matters and is usually left out. (355 studies in our library, 205 in people)
• ⛔ Nothing reverses an already-positive antibody titresolid -- No food reverses a positive ANA, rheumatoid factor, anti-CCP, or any ENA-panel antibody (anti-dsDNA, anti-Sm, SSA/Ro, Scl-70, Jo-1, centromere). Our own `Panels/Autoimmune.md` states this outright, and it is stated here rather than softened because someone with a positive result deserves to know where the leverage genuinely is -- on inflammation and symptoms, not on the titre. (78 studies in our library, 40 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• High SHBG lowers FREE testosterone even when total testosterone reads perfectly normal: low libido, low drive, fatigue, loss of muscle.
• Raised by oestrogen (including the oral contraceptive pill and oral HRT -- but not transdermal), by thyroid overactivity, by liver disease, and by low energy availability.

What people often feel when it runs low

• SHBG produces no symptoms of its own -- it changes what the sex hormones do, so the symptoms are theirs.
• Low SHBG raises FREE testosterone: in women, acne, unwanted hair, scalp thinning, irregular cycles.
• ⚠️ A LOW SHBG IS ONE OF THE EARLIEST AND MOST OVERLOOKED SIGNS OF INSULIN RESISTANCE. Insulin suppresses hepatic SHBG production directly, so a falling SHBG is a metabolic signal appearing in a hormone panel -- often before glucose moves.

Patterns it travels in

• SHBG IS NOT A STANDALONE TEST -- IT IS THE NUMBER THAT MAKES TESTOSTERONE READABLE. Total testosterone normal with a high SHBG means low free testosterone, and the person feels exactly as though their testosterone were low, because functionally it is.
• SHBG LOW + FASTING INSULIN HIGH + TRIGLYCERIDES HIGH + ALT HIGH is the metabolic/fatty-liver picture. SHBG is made in the liver and suppressed by insulin, which is why it belongs to that cluster as much as to the hormone one.
• SHBG LOW + TESTOSTERONE HIGH + LH:FSH RAISED is the PCOS pattern, and the insulin is usually the driver of both.
• SHBG HIGH + ORAL OESTROGEN -- ask before investigating. Oral oestrogen passes through the liver and raises SHBG substantially; transdermal does not. This alone explains a large share of unexpected results.
• SHBG HIGH + FREE T4 HIGH -- thyroid overactivity raises it.
• ⚠️ OUR LIBRARY HOLDS ALMOST NOTHING ON SHBG (19 rows, 4 tagged). Its value here is entirely as an interpretive key for other markers, and that is how it should be presented.

Ingredients with evidence in our library

• Improving insulin sensitivity -- the only reliable leversolid -- SHBG rises as insulin falls. Weight loss, reduced refined carbohydrate, and exercise raise it more dependably than anything taken, because they remove the thing suppressing it. Our library's inositol row (myo- and D-chiro- at 40:1 on hormonal and metabolic parameters) is the closest thing to a supplement answer, and it works through the same insulin route. (19 studies in our library, 12 in people)
• Inositol (myo- and D-chiro-, 40:1)emerging -- Measured on hormonal and metabolic parameters together in our library -- acts on insulin signalling, which is what governs SHBG. (1 studies in our library, 1 in people)
• DIM / indole-3-carbinolemerging -- One human row on oestrogen-related hormones and metabolites. A single study is a signal to watch, not a basis for a recommendation, and it is listed at that weight. (1 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Often no symptoms. A high AMH with irregular cycles, acne and unwanted hair points at PCOS -- more follicles, each producing AMH.

What people often feel when it runs low

• No symptoms at all in most cases -- AMH is a count of remaining follicles, not a hormone with felt effects, and cycles are usually still perfectly regular when it is low.
• Where it is very low, cycles may shorten (from 28 days to 24-25) before they become irregular. That shortening is often the first real-world sign.
• ⚠️ AMH PREDICTS RESPONSE TO OVARIAN STIMULATION. IT DOES NOT PREDICT NATURAL FERTILITY WELL. A low AMH in a woman with regular cycles does not mean she cannot conceive naturally, and it has caused a great deal of unnecessary distress presented as though it did.

Patterns it travels in

• AMH + ANTRAL FOLLICLE COUNT ON ULTRASOUND together are far better than either alone -- one is chemical, one is visual, and they measure the same thing by different routes.
• AMH LOW + FSH HIGH + OESTRADIOL LOW on day 3 is diminished ovarian reserve confirmed three ways.
• AMH HIGH + LH:FSH RAISED + TESTOSTERONE HIGH + SHBG LOW + INSULIN HIGH is the PCOS cluster, where a high AMH is a feature rather than good news.
• AMH IS STABLE ACROSS THE CYCLE, unlike FSH and oestradiol -- so it can be drawn on any day, which is genuinely useful and often not known.
• ⚠️ HORMONAL CONTRACEPTION LOWERS MEASURED AMH by roughly 20-30%. Interpreting a result taken on the pill as a true reserve is a common and consequential error.
• AMH LOW + FERRITIN LOW -- our library holds iron intake measured in relation to ovarian reserve in women seeking infertility treatment. Worth checking rather than assuming.

Ingredients with evidence in our library

• ⛔ No food or nutrient in controlled human trials raises AMH or reverses ovarian reserve decline.solid -- Our brain's food-to-marker matrix calls this one of the clearest 'no lever exists' entries in the entire Labs folder, and tags it [SOLID that no lever exists]. The follicle pool is fixed at birth and non-renewable. This is written plainly because the audience for this marker is often distressed and is being sold things that cannot work. (52 studies in our library, 29 in people)
• CoQ10 -- for oocyte quality, which is a different question from reserveemerging -- Systematic review and meta-analysis of 6 RCTs in 1,529 patients with diminished ovarian reserve. The plausible target is the QUALITY of the follicles that remain and the response to stimulation -- oocytes are the most mitochondria-dense cells in the body. It does not grow the pool back, and the page should not imply it does. (2 studies in our library, 2 in people)
• Iron status and ovulatory functionemerging -- The Nurses' Health Study II found lower ovulatory infertility risk with iron supplementation -- but this is dated and has not been consistently replicated for ovarian reserve specifically. Tagged [EMERGING/dated] in our own matrix, and repeated at that weight here. (1 studies in our library, 1 in people)
• Reducing cadmium and lead exposure -- smoking above allemerging -- Our library holds heavy metal toxicity versus trace element protection in women's reproductive health. Smoking is the single most consistent modifiable association with accelerated reserve decline, and it is a subtraction with better evidence than any addition on this marker. (1 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• HIGH OESTROGEN RELATIVE TO PROGESTERONE: heavy or painful periods, breast tenderness, fluid retention, worsening premenstrual mood, headaches around the period.
• HIGH TESTOSTERONE in women: acne, unwanted hair, scalp thinning, irregular or absent cycles -- the PCOS picture.
• HIGH FSH with low oestradiol is the menopause transition signal.

What people often feel when it runs low

• LOW OESTRADIOL: hot flushes and night sweats, vaginal dryness, poor sleep, low mood, brain fog and word-finding difficulty -- 'word finding difficulty perimenopause' is a captured search phrase, and one of the most under-served questions there is.
• Joint aches that appeared with no injury; skin and hair changing texture.
• LOW PROGESTERONE: shorter cycles, spotting before a period, poor sleep in the second half of the cycle, anxiety that is cyclical rather than constant.
• LOW TESTOSTERONE (in women too): low libido, low drive, loss of muscle tone, flat mood.

Patterns it travels in

• ⚠️ TIMING IS THE WHOLE TEST IN A CYCLING WOMAN. Oestradiol and progesterone mean nothing without knowing the cycle day -- progesterone is measured around day 21 (or 7 days before the expected period) to confirm ovulation happened at all. A random draw is wasted money, and this is the single commonest error with this panel.
• FSH HIGH + OESTRADIOL LOW + cycles changing is the perimenopause-to-menopause signal. In perimenopause FSH swings wildly month to month, so ONE normal FSH does not exclude it.
• LH:FSH RATIO RAISED + TESTOSTERONE HIGH + DHEA-S HIGH + FASTING INSULIN HIGH + SHBG LOW is the PCOS cluster. Insulin is the driver in most cases -- it lowers SHBG, which raises free testosterone, which is why the metabolic markers belong in a hormone panel.
• TESTOSTERONE 'NORMAL' + SHBG HIGH = LOW FREE TESTOSTERONE. Total testosterone alone misses this completely; SHBG is what makes the total number interpretable.
• OESTRADIOL LOW + FSH NORMAL + PROLACTIN HIGH points elsewhere entirely and needs a clinician.
• SEX HORMONES + THYROID + FERRITIN TOGETHER. Thyroid dysfunction and iron deficiency both disrupt cycles and both produce the same fatigue and hair loss -- reading hormones without them attributes to hormones what belongs to iron.
• OESTRADIOL LOW + VITAMIN D LOW -- our library holds vitamin D supplementation measured on fatigue and mood in perimenopausal women specifically (28 rows, 14 human), the largest signal on this marker group.

Ingredients with evidence in our library

• Vitamin Dsolid -- 28 rows, 14 human -- the largest and most human-weighted signal here, measured on fatigue and mood in perimenopausal women directly rather than on hormone levels. (28 studies in our library, 14 in people)
• Ashwagandhasolid -- 15 rows, 10 human -- cognitive and physical function measured in this population. Also lowers the cortisol competing for the same precursor pool. (15 studies in our library, 10 in people)
• Chasteberry (Vitex agnus-castus)solid -- 19 rows, 6 human -- the best-evidenced botanical in our library for premenstrual symptoms specifically, acting on prolactin and the luteal phase rather than on oestrogen. (19 studies in our library, 6 in people)
• Soy isoflavones (genistein, daidzein)mixed -- 9 rows -- systematic review evidence on menopausal symptoms in perimenopausal women. Effect depends heavily on whether someone's gut bacteria produce equol, which is why results vary so much between individuals and between populations. (9 studies in our library, 2 in people)
• Black cohosh (Actaea racemosa)mixed -- 17 rows. Widely used for vasomotor symptoms; our library also holds a meta-analysis finding NO evidence of the hepatotoxicity it has been accused of. Mechanism is not oestrogenic, which matters for who can consider it. (17 studies in our library, 3 in people)
• Magnesium, B vitamins, vitamin C and zinc togetheremerging -- 12 rows, 6 human -- our library holds these measured as a combination on this population rather than singly, which is closer to how they are actually taken. (12 studies in our library, 6 in people)
• Zincemerging -- 15 rows -- systematic review of the correlation between serum zinc and testosterone. Relevant in both sexes, and to the PCOS picture from the other direction. (15 studies in our library, 5 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Frequently NOTHING -- which is the entire reason PSA is measured rather than waited for.
• Where urinary symptoms exist they usually reflect benign enlargement rather than anything sinister: weaker stream, hesitancy, incomplete emptying, getting up at night.
• ⚠️ PSA IS PROSTATE-SPECIFIC, NOT CANCER-SPECIFIC. It rises with benign enlargement, with prostatitis, with a urinary infection, after cycling, after ejaculation within 48 hours, and after any prostate examination or instrumentation. Repeat an unexpected result before acting on it -- a substantial share normalise.

What people often feel when it runs low

• No symptoms. ⚠️ Note that finasteride and dutasteride roughly HALVE PSA -- a result on either must be doubled to be interpreted, and forgetting this hides real findings.

Patterns it travels in

• FREE:TOTAL PSA RATIO adds real information when total PSA is borderline -- a higher free fraction points toward benign enlargement. PSA DENSITY and PSA VELOCITY (rate of change over time) both do more than a single value.
• ⚠️ THE TREND MATTERS MORE THAN THE NUMBER. One PSA is a data point; three over eighteen months is a direction.
• PSA RAISED + urinary symptoms + recent infection -- treat and repeat before escalating.
• PSA + TESTOSTERONE together where testosterone therapy is being considered, since it is a monitoring requirement.
• PSA + VITAMIN D + SELENIUM -- ⚠️ and a caution that belongs here: the SELECT trial found selenium and vitamin E supplementation did NOT prevent prostate cancer, and the vitamin E arm showed a statistically significant INCREASE. Our library holds this. It is the clearest example we have of a plausible mechanism failing at trial, and anyone selling either for prostate health is contradicting the best evidence that exists.
• PSA DECISIONS ARE SHARED DECISIONS. Screening reduces mortality modestly and causes real overdiagnosis harm; the honest framing is a conversation with a doctor, not a recommendation from us.

Ingredients with evidence in our library

• Lycopene (cooked tomato, watermelon)emerging -- 29 rows, 12 human -- the largest signal on this marker in our library, including prospective cohort evidence on intake and prostate cancer risk. Absorption is far better from cooked and oil-containing preparations than from raw tomato. (29 studies in our library, 12 in people)
• Green tea catechins / EGCGemerging -- 6 rows including a prospective randomised trial measuring blood AND prostate tissue concentrations -- unusually direct evidence that the compound reaches the tissue in question. (6 studies in our library, 3 in people)
• ⚠️ Selenium -- the negative result that must travel with itcontested -- 12 rows including 'Selenium for preventing cancer'. The SELECT trial did NOT show prevention, and this is exactly the kind of high-quality negative finding our library exists to keep in front of people rather than quietly omit. (12 studies in our library, 6 in people)
• ⚠️ Vitamin E -- a signal of harm, not benefitcontested -- 15 rows, 11 human. In SELECT, the vitamin E arm showed a statistically significant INCREASE in prostate cancer incidence. This is listed because omitting it would be the dishonest choice, not because it is a recommendation. (15 studies in our library, 11 in people)
• Reishi (Ganoderma lucidum)emerging -- 5 rows -- laboratory work on prostate cancer cell lines. ⚠️ Cell-line evidence is not human evidence, and the Cochrane review of reishi found the human evidence insufficient. Listed at its true weight. (5 studies in our library, 3 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• NONE that anyone can feel. PFAS exposure produces no symptom at any realistic level -- it is found by measurement or by history, never by how someone feels.
• What shows up instead are findings on other tests: raised cholesterol is the most consistently reported association, along with liver enzyme changes and reduced antibody response to vaccination.
• ⚠️ THE HONEST FRAMING IS EXPOSURE, NOT ILLNESS. Essentially everyone tested has detectable PFAS. A detectable level is the normal finding, and presenting it as a personal health crisis is neither accurate nor kind.

What people often feel when it runs low

• No symptoms. Lower is the desirable direction.

Patterns it travels in

• PFAS + CHOLESTEROL is the most consistent association in the literature (24 rows in our library carry both) and it runs in a direction people find surprising -- higher PFAS with higher cholesterol. Causation is not settled and the association is confounded by how both behave in blood.
• PFAS + ALT/GGT -- liver is where PFAS concentrate, and enzyme changes are among the more reproducible findings.
• PFAS + IMMUNOGLOBULIN RESPONSE -- our library holds perfluoroalkyl exposure and IgE in a Korean cohort. Reduced vaccine antibody response is one of the better-supported human effects.
• PFAS + THYROID -- disruption of thyroid hormone binding and transport is a documented mechanism, so thyroid markers belong alongside an exposure panel.
• PFAS + eGFR -- the kidney handles excretion, and reduced filtration raises measured levels without more exposure.
• ⚠️ THE HISTORY IS THE TEST. Drinking water source, occupation, firefighting foam, older non-stick cookware, stain-resistant treatments and grease-proof food packaging tell you more than the number does -- and unlike the number, they can be changed.

Ingredients with evidence in our library

• ⚠️ NOTHING IN THIS LIBRARY REMOVES PFAS FROM A PERSON, AND SAYING OTHERWISE WOULD BE A LIE.solid -- 923 rows name PFAS and only 79 carry any ingredient tag -- the vast majority are exposure, occurrence and toxicology work, not intervention work. PFAS have half-lives measured in years, and there is no supplement with evidence of accelerating that. This is stated first because it is the most important thing on the page. (923 studies in our library, 688 in people)
• Reducing exposure -- the only intervention with evidencesolid -- Filtered drinking water (reverse osmosis and activated carbon both reduce PFAS), replacing worn non-stick cookware, avoiding grease-proof food packaging and stain treatments. This is where the effort belongs. (923 studies in our library, 688 in people)
• Supporting the body's own excretion pathways -- carefully framedemerging -- Per `Labs/Toxicity/DETOX-CLAIMS-POSITION.md`, the strongest claim we may make is supporting endogenous detoxification: the nutrients phase I/II conjugation is built from, and the fibre and fluid that carry products out. Some PFAS undergo enterohepatic recirculation, which is the mechanism behind interest in bile-acid-binding fibre -- our library holds only 3 insoluble-fibre rows on this, so it is a hypothesis worth naming and not a recommendation. (3 studies in our library, 0 in people)
• ⛔ What we do not saysolid -- That any supplement detoxes, removes, pulls or cleanses PFAS. That sauna or exercise clears a body burden. Our own measurement found exercise-and-toxicant-excretion at 4 rows with 0 human-typed -- the weakest claim in the whole detox position, and one we have written down specifically so it is never made.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• At ordinary environmental exposure, none. Aluminium is the third most abundant element in the earth's crust and everyone has some.
• Meaningful accumulation happens overwhelmingly in ONE situation: reduced kidney function, because the kidney is the only meaningful route out. In that setting it affects bone and the nervous system.
• Symptoms where they occur: bone pain and fractures (aluminium interferes with bone mineralisation), muscle weakness, and cognitive change.
• ⚠️ THE ALUMINIUM-AND-DEMENTIA QUESTION IS GENUINELY UNSETTLED, not settled either way. Our library holds a systematic review of metal(loid)s in biospecimens and dementia. Overstating it is dishonest; dismissing it is also dishonest. The accurate word is 'associated, mechanism plausible, causation not established'.

What people often feel when it runs low

• No symptoms. Aluminium has no known biological requirement -- there is no deficiency.

Patterns it travels in

• ALUMINIUM + eGFR IS THE PAIR THAT MATTERS. Reduced filtration is what turns ordinary exposure into accumulation. Reading an aluminium level without kidney function tells you very little.
• ALUMINIUM + PHOSPHATE + CALCIUM -- our library holds aluminium hydroxide's effect on serum phosphate and FGF23 directly. Aluminium-containing antacids and phosphate binders are a real exposure route in people with kidney disease, and the interaction is with bone.
• ALUMINIUM + IRON -- they share transferrin as a transport protein, so IRON DEFICIENCY INCREASES ALUMINIUM UPTAKE. 34 rows in our library carry both. This is the clearest example in the toxicity group of a nutrient deficiency directly increasing an exposure.
• ALUMINIUM + SILICON. Our library's silica wave (2026-09-04) found the specific mechanism: silicic acid forms hydroxyaluminosilicates and increases urinary aluminium excretion -- 'The role of silicic acid in the renal excretion of aluminium' (1996) and 'Silicic acid: its gastrointestinal uptake and urinary excretion in man' (1999). ⛔ THOSE ARE CANDIDATES, NOT YET IN THE APPROVED LIBRARY, and may not be cited on a page until authored and merged.
• ALUMINIUM + MAGNESIUM -- 12 rows, 7 human, mostly antacid pharmacokinetics. Aluminium- and magnesium-containing antacids also change absorption of other medicines, which is a practical point worth more than the toxicology to most people.
• ⚠️ ANTIPERSPIRANTS: our library holds 64 rows on aluminium chloride versus aluminium lactate formulations. Dermal absorption is very low and the breast cancer link has not held up. Say that plainly rather than feeding a fear we cannot support.

Ingredients with evidence in our library

• Correcting iron deficiencyemerging -- 34 rows carry both tags. Aluminium is absorbed via the iron transport system, so iron deficiency increases uptake. Fixing the deficiency reduces the absorption -- a nutrient intervention with a genuine toxicological mechanism behind it. (34 studies in our library, 8 in people)
• Silicon-rich water and orthosilicic acidemerging -- The one place our measurement said a citation wave was genuinely warranted rather than a search fix -- the aluminium-excretion angle was 11 rows with 3 human before the wave. 1,088 candidates were retrieved on 2026-09-04. ⛔ NOT YET AUTHORISED FOR CITATION: every Takeaway must be authored from the abstract and merged first. Until then this is a promising direction, not a claim. (11 studies in our library, 3 in people)
• Reducing intake -- where it actually comes fromsolid -- Aluminium-containing antacids and buffered aspirin are by far the largest oral sources, dwarfing cookware and foil. Processed cheese and some baking powders carry aluminium additives. This is a subtraction that can be made specifically rather than vaguely. (324 studies in our library, 211 in people)
• ⚠️ Kidney function firstsolid -- In anyone with reduced eGFR, avoiding aluminium-containing medicines matters far more than anything added. This is the only group in whom aluminium is a genuine clinical concern. (12 studies in our library, 2 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• In adults, usually SILENT at the levels now common. Where symptoms occur: fatigue, headache, irritability, poor concentration, abdominal pain, joint and muscle aches, high blood pressure.
• In children: reduced attention and learning, behavioural change, and developmental delay -- and ⚠️ THERE IS NO THRESHOLD BELOW WHICH LEAD IS KNOWN TO BE SAFE IN CHILDREN. Effects are measurable at levels once called normal.
• Anaemia that does not respond to iron -- lead interferes with haem synthesis directly.
• A blue line at the gum margin is the classic textbook sign and is essentially never seen now.

What people often feel when it runs low

• No symptoms. Lead has no biological function -- there is no deficiency, and lower is always better.

Patterns it travels in

• ⚠️ LEAD + FERRITIN IS THE MOST IMPORTANT PAIR IN THE ENTIRE TOXICITY GROUP. Iron deficiency UPREGULATES the divalent metal transporter that absorbs lead, so an iron-deficient child absorbs several times more lead from the same environment. Correcting iron is genuinely protective -- it is prevention, not detox, and it is the strongest nutrition claim we can make about lead.
• LEAD + CALCIUM -- the same competition. Adequate calcium reduces lead absorption, and in pregnancy adequate calcium reduces mobilisation of stored lead out of the mother's skeleton into the blood.
• LEAD + ZINC -- 21 rows, 8 human, the largest ingredient signal here. Zinc competes with lead at absorption and at the enzymes lead poisons.
• LEAD + HAEMOGLOBIN + MCV -- lead blocks haem synthesis, producing anaemia that iron alone will not fix while exposure continues.
• LEAD + eGFR + URIC ACID + BLOOD PRESSURE -- chronic low-level lead is associated with reduced filtration, raised urate and hypertension. This is where adult lead actually matters.
• ⚠️ BLOOD LEAD MEASURES RECENT EXPOSURE, roughly the last 30 days. Most of the body's lead is in bone with a half-life of decades, and a normal blood lead does not exclude a significant past burden. Bone lead is research-grade, not routine.
• THE HISTORY IS THE TEST: housing built before 1978, renovation of old paint, occupation, imported cosmetics and spices, traditional remedies, water pipes, shooting ranges.

Ingredients with evidence in our library

• Correcting iron deficiency -- the strongest claim we can makesolid -- 11 rows, 6 human. Iron deficiency increases lead absorption through the shared DMT1 transporter. This is prevention with a clear mechanism, and it is particularly consequential in children, who are the population that matters most here. (11 studies in our library, 6 in people)
• Adequate calciumsolid -- 8 rows. Competes with lead at absorption, and in pregnancy reduces skeletal lead mobilisation into blood -- protecting the fetus from the mother's own stored exposure. (8 studies in our library, 3 in people)
• Zincemerging -- 21 rows, 8 human -- the largest ingredient signal on this marker in our library, from children's health modelling around smelter sites. Competes with lead at absorption and at the enzymes it inhibits. (21 studies in our library, 8 in people)
• Vitamin C and vitamin Eemerging -- 14 rows across both tags -- supplementation measured on oxidative damage and total antioxidant capacity in lead-exposed people. This addresses the oxidative consequence of exposure, NOT the lead itself, and the distinction matters. (14 studies in our library, 2 in people)
• Seleniumemerging -- 11 rows, 5 human, including groundwater chemistry and children's blood lead levels. (11 studies in our library, 5 in people)
• ⛔ Removing the source is the only thing that lowers the burdensolid -- Chelation is a medical treatment for high levels with real risks, prescribed and monitored -- never a supplement. Per our detox position, no product may be described as removing lead. What nutrition does here is reduce ABSORPTION, and that framing is both accurate and genuinely useful.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Often silent at dietary levels. Where symptoms occur: tingling or numbness in hands, feet and around the mouth, tremor, poor coordination, headache, fatigue, irritability and difficulty concentrating.
• Metallic taste; in higher exposures, mouth and gum problems.
• ⚠️ TWO DIFFERENT MERCURIES BEHAVE DIFFERENTLY. Methylmercury from fish accumulates in nerve tissue and crosses the placenta -- it is the one that matters for pregnancy. Inorganic and elemental mercury (dental amalgam, occupational, some skin-lightening creams) concentrate in the kidney instead. A total blood mercury does not distinguish them, and speciated testing does.

What people often feel when it runs low

• No symptoms. Mercury has no biological function -- there is no deficiency.

Patterns it travels in

• MERCURY + SELENIUM IS THE CENTRAL RELATIONSHIP, and it is the largest signal in our library on this marker (114 rows). Selenium binds mercury with extraordinary affinity -- so mercury both is buffered BY selenium and DEPLETES functional selenium, disabling the selenoenzymes (glutathione peroxidase, the thyroid deiodinases) that depend on it. High mercury can therefore produce a functional selenium deficiency at a normal-looking selenium level.
• THIS IS WHY OILY FISH ARE NOT SIMPLY A MERCURY RISK. Salmon, sardines and anchovies carry far more selenium than mercury; large predatory fish (swordfish, king mackerel, shark, bigeye tuna) carry the reverse. The species matters more than the category, and telling people to avoid fish is worse advice than telling them which fish.
• MERCURY + OMEGA-3 INDEX -- the same food supplies both. Advice that ignores this trades a documented benefit for a speculative harm, particularly in pregnancy where DHA matters most.
• MERCURY + GLUTATHIONE -- 35 rows. Glutathione conjugation is the main excretion route, which is why glutathione status is the relevant nutritional question rather than any binder.
• MERCURY + THYROID -- deiodinases are selenoenzymes, so mercury reaches thyroid function through the selenium route.
• MERCURY + eGFR -- inorganic mercury concentrates in the kidney; check filtration where occupational exposure is plausible.
• THE HISTORY IS THE TEST: fish species and frequency, dental amalgam load, occupation, skin-lightening creams (a genuinely serious and under-recognised source), and broken compact fluorescent bulbs.

Ingredients with evidence in our library

• Seleniumsolid -- 114 rows, 15 human -- the dominant relationship on this marker. Adequate selenium status is the best-supported nutritional buffer against mercury's effects, because the mechanism of harm is largely selenoenzyme inhibition. ⚠️ Selenium has a narrow safe window; this is an argument for adequacy, not for high doses. (114 studies in our library, 15 in people)
• Choosing smaller, shorter-lived fishsolid -- The single most effective intervention, and it keeps the omega-3s. Sardines, anchovies, salmon, herring and mackerel sit at the favourable end of the selenium-to-mercury ratio; large predators sit at the other. A substitution rather than a subtraction. (455 studies in our library, 176 in people)
• Glutathione precursors -- NAC, glycine, sulfur amino acidsemerging -- 35 rows. Mercury is excreted as a glutathione conjugate, so supplying what the body builds glutathione from supports the route that actually exists. Framed per the spec's antioxidant rule: the raw materials, not the antioxidant itself. (35 studies in our library, 6 in people)
• Zincemerging -- 62 rows, 9 human. Induces metallothionein, the protein that binds and sequesters heavy metals -- a real mechanism, measured mostly in animals. (62 studies in our library, 9 in people)
• ⛔ What we do not saymixed -- That any supplement removes mercury. Per `Labs/Toxicity/DETOX-CLAIMS-POSITION.md`, sweat has 34 rows with 12 human-typed as a genuine excretion route with measured metal content -- but no study shows sauna clears a body burden, and we do not claim it does. (34 studies in our library, 12 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• PROTEIN IN URINE: foamy or frothy urine that persists, swelling of ankles and around the eyes. Often completely silent, which is why it is tested rather than waited for.
• BLOOD IN URINE: sometimes visible, more often not. ⚠️ Visible blood always needs a doctor, even once, even painless -- especially painless.
• GLUCOSE IN URINE: thirst and frequent urination; means blood glucose has exceeded the kidney's reabsorption threshold, or an SGLT2 medication is being taken.
• LEUKOCYTES AND NITRITES: burning, urgency, frequency, cloudy urine -- infection.
• KETONES: fasting, low-carbohydrate eating, or illness. In someone with diabetes and high glucose, ketones are urgent.
• HIGH SPECIFIC GRAVITY: concentrated urine -- dehydration. Dark yellow tells you the same thing for free.

What people often feel when it runs low

• LOW SPECIFIC GRAVITY: dilute urine -- usually just a lot of fluid, but persistently dilute urine with high volumes can reflect a concentrating problem.

Patterns it travels in

• URINE ALBUMIN-TO-CREATININE RATIO IS THE MOST UNDER-ORDERED USEFUL TEST IN THIS WHOLE PANEL. Albuminuria appears years before eGFR falls -- it is the earliest kidney signal available, and it costs almost nothing. A dipstick protein is far less sensitive; ask for the ACR specifically.
• PROTEIN IN URINE + ALBUMIN LOW IN BLOOD -- the kidney is losing it rather than the liver failing to make it. That pairing resolves the question immediately.
• PROTEIN + eGFR FALLING + BLOOD PRESSURE HIGH + GLUCOSE HIGH is the commonest kidney trajectory there is, and every element of it is modifiable.
• GLUCOSE IN URINE + NORMAL BLOOD GLUCOSE = an SGLT2 inhibitor, or a rare low renal threshold. Ask about medication first.
• SPECIFIC GRAVITY CHANGES THE MEANING OF EVERY OTHER URINE RESULT. Concentrated urine exaggerates all of them; dilute urine hides them. Read it first -- our library holds hydration status and hydration biomarkers among physically active people directly.
• ⚠️ HYDRATION ALSO DISTORTS BLOOD MARKERS -- haemoglobin, haematocrit, sodium, creatinine and albumin all read high when dehydrated. A urinalysis is a cheap sanity check on the rest of the panel.

Ingredients with evidence in our library

• Water intake, matched to sodium and activitysolid -- 7 rows, 3 human on hydration behaviours and biomarkers in physically active people. ⚠️ More water is not automatically better -- exercise-associated hyponatraemia comes from drinking too much plain water while losing sodium in sweat. Replace what was lost, not simply more. (7 studies in our library, 3 in people)
• Sodium reduction, for protein in urinesolid -- Lowering sodium lowers glomerular pressure and albuminuria -- the same intervention that carries the largest signal on the kidney filtration panel. (31 studies in our library, 17 in people)
• Curcuminemerging -- Our library holds curcumin attenuating proteinuria in patients -- 2 rows, both human. Small, specific, and listed at that weight. (2 studies in our library, 2 in people)
• Vitamin Demerging -- An umbrella review on supplementation in diabetic kidney disease, where albuminuria is the endpoint. (3 studies in our library, 1 in people)
• ⚠️ The library is thin here (190 rows, 41 tagged) and the reason is structuralmixed -- Urinalysis is a screening instrument rather than an intervention target -- studies act on what it detects (kidney function, glucose, infection, hydration), not on the test. The evidence for each of those lives under its own marker, which is where it should be read. (190 studies in our library, 77 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• No symptoms specific to the number -- biological age is a computed summary, not a sensation.
• What tends to travel with an accelerated result: poor sleep, low fitness, high inflammation, poor metabolic health, smoking, and high stress load. Each of those is measurable and modifiable on its own.
• ⚠️ THE MOST IMPORTANT CAVEAT ON THIS MARKER: different clocks disagree with each other, sometimes by many years, on the same sample. They are not measuring one agreed thing. Treat a single result as a conversation starter, not a verdict, and never let it frighten someone.

What people often feel when it runs low

• A younger-than-chronological result is encouraging and, on the same caveat, should not be over-read either.

Patterns it travels in

• THE TREND IS THE ONLY USE. A single epigenetic age is noisy; the same clock on the same person over two or three years says something a one-off cannot. Compare like with like -- never compare across different clocks.
• BIOLOGICAL AGE ACCELERATED + HS-CRP HIGH + FASTING INSULIN HIGH + POOR SLEEP is the actionable version of this result. The composite is downstream of things that each have their own marker and their own evidence base.
• BIOLOGICAL AGE + VO2 MAX / GRIP STRENGTH -- cardiorespiratory fitness and grip strength predict mortality at least as well as any current epigenetic clock, and both are free to measure. Worth saying, because it keeps an expensive test in proportion.
• TELOMERE LENGTH AND METHYLATION CLOCKS ARE NOT THE SAME MEASUREMENT and correlate only weakly. Reporting them as interchangeable is a common error.
• ⚠️ DO NOT BUILD A PLAN ON THIS MARKER. Build it on the markers underneath it -- glucose, insulin, inflammation, lipids, sleep, fitness -- which is where every intervention with real evidence actually acts.

Ingredients with evidence in our library

• Polyphenol-rich dietary patternsemerging -- Our library holds the effect of polyphenols on DNA-methylation-assessed biological age attenuation from the DIRECT-PLUS trial line -- one of very few interventions measured on a methylation clock as a pre-specified outcome rather than found afterwards. (2 studies in our library, 2 in people)
• Mediterranean-pattern eatingsolid -- The dietary pattern with the largest and oldest evidence base for the outcomes biological-age clocks are trying to predict -- PREDIMED-level cardiovascular evidence sits under it. A pattern, not a pill, which is the consistent finding across our whole Labs folder. (387 studies in our library, 200 in people)
• Fermented foods, for the inflammatory halfsolid -- The Stanford RCT (36 healthy adults, 10 weeks, Cell 2021) found a fermented-food diet increased microbial diversity and lowered 19 inflammatory proteins including IL-6, while an equally high-fibre diet did not move diversity in the same window. Inflammation is one of the strongest inputs to every ageing clock. (1 studies in our library, 1 in people)
• Omega-3 (EPA/DHA)emerging -- A randomised controlled trial on omega-3, oxidative stress and leukocyte telomere length. ⚠️ Telomere length is a DIFFERENT measurement from methylation age and the two correlate only weakly -- reporting them as interchangeable is a common error. (2 studies in our library, 1 in people)
• The interventions with the largest evidence are not purchasablesolid -- Not smoking, cardiorespiratory fitness, sleep duration and regularity, maintaining muscle mass, and metabolic health. VO2 max and grip strength predict mortality at least as well as any current epigenetic clock and cost nothing to measure -- worth saying, because it keeps an expensive test in proportion. (387 studies in our library, 200 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• HIGH TSH = UNDERACTIVE THYROID -- the counterintuitive part people get wrong constantly. TSH is the pituitary shouting; the louder it shouts, the less the thyroid is delivering.
• Cold hands and feet, needing more layers than everyone else. Fatigue sleep does not fix. Weight gain of a few kilos with no change in eating.
• Constipation, dry skin, brittle nails, hair thinning or loss of the outer third of the eyebrow.
• Brain fog, slowed thinking, low mood -- routinely mistaken for depression.
• Heavier or longer periods; reduced fertility; muscle aches and cramps; hoarse voice; puffiness around the eyes.

What people often feel when it runs low

• LOW TSH = OVERACTIVE THYROID, or too much thyroid medication -- the commoner cause in anyone already treated.
• Palpitations, tremor, anxiety and inner restlessness, heat intolerance, weight loss with good appetite, loose stools, trouble falling asleep.
• ⚠️ SUPPRESSED TSH IS NOT A HARMLESS OVERSHOOT -- over years it costs bone density and raises atrial fibrillation risk. It needs a dose conversation.

Patterns it travels in

• ⛔ IN THIS PANEL, THE WHOLE POINT IS THAT TSH ALONE IS NOT A THYROID PANEL. TSH plus free T4 plus free T3 plus TPO antibodies is -- and this panel adds the four nutrient cofactors on top, because they are what the gland is built from.
• TSH CAN SIT IN RANGE WHILE FREE T3 IS LOW. That is the commonest reason someone with every symptom is told their thyroid is fine.
• TSH HIGH + FREE T4 NORMAL is subclinical -- the pituitary compensating and succeeding. This is the window where nutrient status matters most and where our library's evidence is strongest (selenium 18 rows, 11 human).
• TSH HIGH + TPO ANTIBODIES POSITIVE names the mechanism as autoimmune. Antibodies often precede the TSH change by years.
• TSH HIGH + FERRITIN LOW -- thyroid peroxidase is a haem enzyme. Under-recognised, and it blunts the response to replacement.
• TSH HIGH + LDL/APOB HIGH -- hypothyroidism slows LDL-receptor clearance. Check thyroid before treating lipids as a diet problem.
• ⚠️ BIOTIN INTERFERES WITH THE ASSAY -- high-dose biotin makes TSH read falsely LOW and free T4 falsely HIGH. Stop it 48-72 hours before the draw.
• ⚠️ TSH HAS A DIURNAL RHYTHM, highest overnight and early morning. Draw consistently, and early, if trends are being compared.

Ingredients with evidence in our library

• Seleniumsolid -- 18 rows, 11 human -- the best-evidenced nutrient on thyroid function in our library, studied with zinc in subclinical hypothyroidism. The deiodinases that activate T4 are selenoproteins, and glutathione peroxidase protects the gland from the peroxide it must generate. Two Brazil nuts a day supplies the dose; the window is narrow and more is not better. (18 studies in our library, 11 in people)
• ⚠️ Iodine -- the clearest U-shaped nutrient in the whole panelmixed -- 22 rows, 8 human. Substrate for the hormone -- but too little causes hypothyroidism and so does too much, which can also trigger autoimmunity in susceptible people. Do not supplement iodine on symptoms alone, and never before selenium. (22 studies in our library, 8 in people)
• Zincsolid -- 9 rows, 5 human. Required for deiodinase activity and for receptor binding. (9 studies in our library, 5 in people)
• Ironsolid -- Thyroid peroxidase is a haem enzyme; without iron it cannot build hormone. Assessed in our library alongside ferritin and thyroid profile directly. (3 studies in our library, 2 in people)
• Myo-inositol with seleniumemerging -- Compared head-to-head against selenium alone in Hashimoto's with subclinical hypothyroidism -- the combination outperformed selenium alone on TSH. (4 studies in our library, 2 in people)
• ⚠️ Ashwagandha -- right herb, wrong direction for someemerging -- 2 rows, both human, in a systematic review of randomised herbal trials in hypothyroidism. It RAISES thyroid output, which makes it actively wrong for anyone with a low TSH or on replacement. (2 studies in our library, 2 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Palpitations, tremor, heat intolerance, anxiety, weight loss, loose stools, poor sleep.

What people often feel when it runs low

• The hypothyroid picture -- cold, fatigue, fog, constipation, dry skin, hair thinning, heavy periods, low mood.

Patterns it travels in

• FREE T4 IS THE PRODUCTION NUMBER; FREE T3 IS THE ACTIVATION NUMBER. Free T4 normal with free T3 low is a conversion problem, not a production one -- and that distinction changes what is worth doing entirely.
• FREE T4 LOW + TSH HIGH is overt hypothyroidism. FREE T4 NORMAL + TSH HIGH is subclinical, and is where nutrient status is most worth checking.
• FREE T4 LOW + TSH LOW OR NORMAL points at the pituitary rather than the thyroid, and needs a clinician.
• FREE T4 IS PREFERRED OVER TOTAL T4 because carrier-protein changes -- oral oestrogen, pregnancy, liver disease -- move the total without changing thyroid function.
• ⚠️ TIMING ON REPLACEMENT: draw before the morning levothyroxine dose. A sample taken 2-4 hours after a dose reads artificially high and has caused many unnecessary dose reductions.
• ⚠️ BIOTIN makes free T4 read falsely HIGH -- stop 48-72 hours before.

Ingredients with evidence in our library

• Iodine, as substratemixed -- 13 rows, 4 human. Free T4 is the hormone iodine is literally built into -- four iodine atoms per molecule. U-shaped: too much is as much a problem as too little. (13 studies in our library, 4 in people)
• Ironsolid -- Thyroid peroxidase is a haem enzyme and does the iodination. Our library holds iron deficiency and thyroid function measured directly in pregnancy. (1 studies in our library, 1 in people)
• Seleniumsolid -- 17 rows, 6 human. Protects the gland during synthesis via glutathione peroxidase, and governs what happens to T4 afterwards. (17 studies in our library, 6 in people)
• ⚠️ Separate levothyroxine from iron, calcium, magnesium and coffeesolid -- All of them reduce its absorption. Four hours from minerals, and an hour from food and coffee. This single instruction resolves a meaningful share of 'my dose isn't working'. (141 studies in our library, 27 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• The overactive picture -- palpitations, tremor, heat intolerance, anxiety, weight loss, loose stools, poor sleep.

What people often feel when it runs low

• The underactive picture -- cold, fatigue, fog, constipation, dry skin, hair thinning, heavy periods.

Patterns it travels in

• ⚠️ TOTAL T4 IS THE WEAKER TEST AND FREE T4 IS THE ONE TO ORDER. Total T4 measures hormone bound to carrier proteins plus the tiny free fraction that is actually active -- so anything that changes carrier protein levels changes the total without changing thyroid function at all.
• TOTAL T4 HIGH + NORMAL FREE T4 = raised thyroxine-binding globulin, not thyroid disease. Caused by oral oestrogen (the pill, oral HRT), pregnancy, and liver disease.
• TOTAL T4 LOW + NORMAL FREE T4 = low binding globulin -- androgens, steroids, nephrotic syndrome, severe illness.
• TOTAL T4 retains a use in monitoring where free-hormone assays are unreliable, and in some pregnancy protocols where the reference ranges shift predictably.

Ingredients with evidence in our library

• ⚠️ Our library holds almost nothing on total T4 specifically -- 11 rows.mixed -- That is expected rather than alarming: the research literature moved to free hormone measurement decades ago. The nutrient evidence that matters (selenium, iodine, zinc, iron) sits under free T4, free T3 and TSH, which is where it should be read. (11 studies in our library, 4 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Palpitations, tremor, heat intolerance, anxiety, weight loss, loose stools.

What people often feel when it runs low

• The hypothyroid picture EVEN WHEN TSH READS NORMAL -- cold, flat, foggy, constipated, dry-skinned, losing hair.
• Free T3 tracks how someone FEELS better than TSH does, because T3 is the active hormone the tissues actually use.
• A distinct pattern in dieters and endurance athletes: free T3 falls first when energy availability drops. That is adaptive down-regulation, not disease, and it corrects with food rather than iodine.

Patterns it travels in

• FREE T4 NORMAL + FREE T3 LOW IS A CONVERSION QUESTION. Selenium, zinc and iron are the cofactors for that step -- which is exactly what this panel's 17 selenium rows and 5 zinc rows are about. Cortisol and inflammation both suppress the same step.
• FREE T3 LOW + REVERSE T3 HIGH + CORTISOL RAISED is the stress and illness pattern -- T4 deliberately routed to the inactive form.
• FREE T3 LOW + FERRITIN LOW -- iron is a conversion cofactor as well as a synthesis one.
• IODINE + SELENIUM + ZINC MEASURED TOGETHER -- our library holds a study assessing exactly this joint impact on third-trimester thyroid function.
• ⚠️ FREE T3 IS THE MARKER MOST OFTEN LEFT OFF A PANEL AND MOST OFTEN THE ONE THAT EXPLAINS THE SYMPTOMS.
• ⚠️ FREE T3 IS THE LEAST RELIABLE OF THE THYROID ASSAYS technically -- interpret a borderline value alongside symptoms rather than as a precise number.

Ingredients with evidence in our library

• Seleniumsolid -- 17 rows, 6 human -- the largest signal on this marker. The deiodinases that convert storage T4 into active T3 are selenoproteins. This is the most mechanistically direct nutrient-to-marker link in the whole thyroid group. (17 studies in our library, 6 in people)
• Zincsolid -- 5 rows, 3 human. Required for deiodinase activity and receptor binding; assessed jointly with iodine and selenium. (5 studies in our library, 3 in people)
• Ironsolid -- Haem-dependent thyroid peroxidase, measured on the iron-deficiency-and-thyroid-function relationship directly. (1 studies in our library, 1 in people)
• Probiotics and synbioticsemerging -- 2 rows -- oral supplementation moved thyroid function in adults. A meaningful fraction of T4-to-T3 conversion happens via gut bacterial sulfatases, which is the mechanism behind an otherwise surprising result. (2 studies in our library, 1 in people)
• Adequate energy intakesolid -- Free T3 is the marker that falls first in restriction and over-training. Where that is the cause, more food raises it and no supplement will. (141 studies in our library, 27 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Palpitations, tremor, heat intolerance, anxiety, weight loss.

What people often feel when it runs low

• Cold, fatigue, fog, low mood, constipation, and the whole low-T3 picture -- which frequently appears with a completely normal TSH.

Patterns it travels in

• ⚠️ SAME CARRIER-PROTEIN PROBLEM AS TOTAL T4 -- free T3 is the better test for the same reason.
• TOTAL T3 has one genuine advantage: in some assays free T3 is technically unreliable, and total T3 remains useful for confirming hyperthyroidism, particularly T3-toxicosis where T4 is normal and T3 alone is raised.
• TOTAL T3 LOW in acute illness or prolonged energy restriction is non-thyroidal illness -- deliberate down-regulation, not disease. Treating it as hypothyroidism is a real and common error.

Ingredients with evidence in our library

• ⚠️ 6 rows in the entire approved library.contested -- The thinnest count of any marker measured in this whole exercise, and it reflects the assay's status rather than the biology. Read the conversion evidence -- selenium, zinc, iron, cortisol -- under free T3. (6 studies in our library, 2 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• The claim is that high reverse T3 blocks active T3 and causes hypothyroid symptoms with normal standard labs -- cold, fatigue, fog, weight gain.
• ⚠️ THIS IS CONTESTED, AND THE PAGE SHOULD SAY SO PLAINLY. Reverse T3 rises reliably in acute illness, starvation, prolonged calorie restriction, over-training, and after surgery -- it is a MARKER of the body down-regulating deliberately. Mainstream endocrinology does not accept it as a treatable target, and there is no outcome trial showing that lowering it helps anyone.

What people often feel when it runs low

• No recognised significance.

Patterns it travels in

• REVERSE T3 HIGH + FREE T3 LOW + TSH NORMAL is the non-thyroidal illness / low-T3 syndrome pattern. It is real physiology. What is contested is whether it should be treated, and the honest answer is that the evidence does not support treating it as thyroid disease.
• REVERSE T3 HIGH + CORTISOL HIGH -- cortisol drives T4 down the reverse-T3 route. This is the mechanism, and it points at load, sleep and energy availability rather than at the thyroid.
• REVERSE T3 HIGH + FERRITIN LOW + prolonged dieting or high training load -- the commonest real-world cause combination, and the one that responds to more food and more rest.
• ⚠️ THE FREE T3 : REVERSE T3 RATIO is popular in functional medicine and has no agreed reference range, no assay standardisation, and no outcome evidence. Presenting it as a validated number would be misleading.

Ingredients with evidence in our library

• ⚠️ 10 rows, 3 tagged, none human-typed -- and the honest position is that nothing here is established.contested -- Selenium and iodine appear because they belong to the deiodinase enzymes that produce reverse T3, but no trial in our library shows a supplement lowering reverse T3 to anyone's benefit. Claiming otherwise would be inventing evidence. (10 studies in our library, 4 in people)
• Adequate energy intake and recoveryemerging -- The mechanism points here rather than at a bottle: reverse T3 rises when the body decides to spend less. More food, more sleep, less training load. It is unglamorous and it is what the physiology actually says.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• No recognised significance.

What people often feel when it runs low

• The claim: a low free T3 to reverse T3 ratio means T4 is being routed to the inactive form, producing hypothyroid symptoms with normal standard labs -- cold, fatigue, fog, weight gain.
• ⚠️ THIS RATIO HAS NO AGREED REFERENCE RANGE, NO ASSAY STANDARDISATION AND NO OUTCOME EVIDENCE. Presenting it as a validated number would be misleading. The underlying physiology -- that illness, starvation, over-training and cortisol shift conversion toward reverse T3 -- is real and well documented. Whether the ratio should be treated is not established.

Patterns it travels in

• LOW RATIO + HIGH CORTISOL + PROLONGED RESTRICTION OR HEAVY TRAINING is the coherent story, and it points at energy availability and recovery rather than at the thyroid.
• LOW RATIO + ACUTE OR RECENT ILLNESS is non-thyroidal illness syndrome -- deliberate, adaptive down-regulation. Treating it as thyroid disease is a recognised error.
• ⚠️ BOTH ASSAYS CARRY MEASUREMENT ERROR, and dividing one by the other compounds it. A ratio built from two imprecise numbers is less reliable than either.
• IF THE RATIO IS LOW, CHECK THE COFACTORS THAT ACTUALLY DRIVE CONVERSION -- selenium, zinc, iron -- since those have real evidence behind them and a real deficiency is worth correcting on its own terms.

Ingredients with evidence in our library

• ⚠️ Nothing is established to move this ratio to anyone's benefitcontested -- Our library holds 10 rows on reverse T3, 3 tagged, none human-typed. Selenium and iodine appear because they belong to the deiodinase enzymes, not because a trial showed benefit. Saying so is the honest position. (10 studies in our library, 4 in people)
• Selenium, zinc and iron -- the conversion cofactors, worth correcting on their own meritssolid -- The deiodinases that convert T4 to T3 are selenoproteins; zinc is required for their activity and for receptor binding; thyroid peroxidase is a haem enzyme. Correcting a measured deficiency in any of these is worth doing regardless of what the ratio says. (18 studies in our library, 11 in people)
• Adequate energy intake and recoveryemerging -- The mechanism points here rather than at a bottle. Reverse T3 rises when the body decides to spend less -- more food, more sleep, less training load.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Often NONE for years -- antibodies commonly precede any change in TSH or in how someone feels by a long time. That is the argument for measuring them early.
• Where symptoms exist they are the hypothyroid ones, appearing while TSH still reads normal.
• A swollen or tender feeling at the front of the neck.
• Symptoms that swing between over- and under-active early on, as the gland releases stored hormone during flares.
• A personal or family history of other autoimmune conditions -- coeliac disease, type 1 diabetes, vitiligo, rheumatoid arthritis.

What people often feel when it runs low

• Negative antibodies are the desired result.

Patterns it travels in

• TPO ANTIBODIES POSITIVE + TSH NORMAL is the earliest actionable finding in the thyroid group -- autoimmunity underway, function still compensated. It is where selenium has its best evidence and where nothing else needs doing yet.
• TPO IS THE MORE SENSITIVE ANTIBODY; THYROGLOBULIN ANTIBODY ADDS A LITTLE. Where only one is ordered, order TPO.
• ANTIBODIES POSITIVE + FERRITIN LOW is common and bidirectional -- autoimmune thyroid disease coexists with autoimmune gastritis and coeliac disease, both of which impair iron absorption.
• ANTIBODIES POSITIVE + B12 LOW / MMA HIGH -- the same autoimmune gastritis removes intrinsic factor and with it B12 absorption.
• ANTIBODIES POSITIVE + VITAMIN D LOW is a consistent association, with treatment moving function and autoimmunity markers together.
• ⚠️ ANTIBODIES DO NOT NEED RE-MEASURING OFTEN. The titre fluctuates and chasing it wastes money; what matters is whether FUNCTION is changing.
• ⚠️ A POSITIVE TPO IN PREGNANCY raises miscarriage and postpartum thyroiditis risk and warrants closer TSH monitoring -- one of the few places the antibody itself changes management.

Ingredients with evidence in our library

• Seleniumsolid -- The strongest nutrient-to-autoimmunity signal in our entire library -- 31 rows, 17 human. Repletion lowers TPO antibody titres in multiple randomised trials, with the effect appearing at 3-6 months and sometimes fading with long-term use. Mechanism: glutathione peroxidase protecting the gland from its own hydrogen peroxide. Two Brazil nuts a day; the window is genuinely narrow. (31 studies in our library, 17 in people)
• Myo-inositol with seleniumemerging -- Head-to-head against selenium alone in Hashimoto's with subclinical hypothyroidism; the combination did more. (4 studies in our library, 2 in people)
• Vitamin Demerging -- 6 rows, 3 human -- treatment moved thyroid function and autoimmunity markers together. Meta-analyses show reduced antibody titres, especially in people who start out deficient. (6 studies in our library, 3 in people)
• Ironsolid -- 7 rows, 3 human -- iron and ferritin deficiency in women with hypothyroidism and chronic lymphocytic thyroiditis. Correcting it improves symptoms and the response to replacement. (7 studies in our library, 3 in people)
• ⚠️ Iodine -- the one to be cautious about herecontested -- 13 rows, 5 human. Excess iodine can TRIGGER or worsen thyroid autoimmunity in susceptible people. With positive antibodies this is the nutrient to be careful with rather than enthusiastic about -- the opposite of the supplement-aisle instinct. (13 studies in our library, 5 in people)
• Screening for coeliac diseasesolid -- Autoimmunity clusters, and coeliac disease is both common in this group and definitively treatable. Check tTG-IgA with total IgA. (78 studies in our library, 40 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Same picture as TPO antibodies -- frequently silent for years, then the hypothyroid symptoms appearing while TSH still reads normal.
• Thyroglobulin antibodies are LESS SENSITIVE than TPO for autoimmune thyroid disease, and are positive alone in only a minority.

What people often feel when it runs low

• Negative is the desired result.

Patterns it travels in

• ⛔ THE ONE RULE THIS MARKER EXISTS FOR: THYROGLOBULIN ANTIBODIES MUST BE MEASURED WHENEVER THYROGLOBULIN ITSELF IS. The antibodies interfere with the assay and make thyroglobulin read falsely LOW -- which in thyroid cancer surveillance means missed recurrence. This is the strictest pairing rule in the library.
• TgAb POSITIVE + TPO POSITIVE is the usual combination; TgAb positive ALONE is less common and less specific.
• TgAb POSITIVE + MAGNESIUM SEVERELY LOW -- our library holds this specific association (1 row, human).
• TgAb POSITIVE + FERRITIN LOW + B12 LOW is the autoimmune-gastritis cluster.
• ⚠️ LIKE TPO, THE TITRE FLUCTUATES AND DOES NOT NEED CHASING. Function is what matters.

Ingredients with evidence in our library

• Seleniumsolid -- 31 rows, 17 human -- meta-analyses of RCTs show reliable TPOAb and TgAb reduction at 3-6 months, and our brain calls this the single best-evidenced nutrient-antibody relationship in the entire Labs folder. The effect can fade with long-term use, which is worth knowing. (31 studies in our library, 17 in people)
• Vitamin Demerging -- Meta-analyses show reduced antibody titres, especially in those starting out deficient. (6 studies in our library, 3 in people)
• Magnesiumemerging -- The one direct association our library holds on this specific antibody -- severely low serum magnesium with positive anti-thyroglobulin antibodies. A reason to check, not a demonstrated lever. (1 studies in our library, 1 in people)
• ⚠️ Iodine, cautiouslycontested -- Excess can worsen autoimmunity in susceptible people. Correct selenium first, always. (13 studies in our library, 5 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• The overactive picture: racing or irregular heartbeat, tremor, anxiety and inner restlessness, heat intolerance and sweating, weight loss with a good appetite, loose stools, poor sleep, muscle weakness in the thighs.
• Eye changes -- gritty, bulging or aching eyes, double vision, lid retraction. Thyroid eye disease is driven by the same antibody acting on tissue behind the eye, and it can appear before, during or after the thyroid becomes overactive.
• A smooth, diffusely enlarged thyroid.
• ⚠️ AN OVERACTIVE THYROID IS A MEDICAL CONDITION NEEDING TREATMENT, not a nutrition project. Untreated it costs bone density and carries a real risk of atrial fibrillation.

What people often feel when it runs low

• A negative result is the expected one and carries no symptoms.

Patterns it travels in

• TSI/TRAb POSITIVE + TSH SUPPRESSED + FREE T4 AND/OR FREE T3 HIGH is Graves' disease -- this antibody is what distinguishes it from other causes of an overactive thyroid, and that distinction changes treatment entirely.
• TSI/TRAb is also the test that predicts relapse after stopping antithyroid medication, and it is the one that matters in pregnancy because the antibody crosses the placenta.
• ⚠️ IODINE IS THE NUTRIENT TO BE MOST CAREFUL WITH HERE, and the direction is the opposite of the usual instinct. Extra iodine can worsen an overactive thyroid. Kelp, high-dose iodine supplements and iodine-containing 'thyroid support' formulas are actively the wrong thing in this pattern -- and they are exactly what someone with thyroid symptoms tends to buy.
• TSI/TRAb POSITIVE + SELENIUM LOW -- selenium has evidence in mild thyroid eye disease specifically, which is one of the few nutrition claims in this area that holds up.

Ingredients with evidence in our library

• Seleniumemerging -- 5 rows, 2 human -- including a prospective randomised trial adding L-carnitine and selenium to methimazole in Graves' disease. Selenium also has trial evidence in mild thyroid eye disease. This is adjunctive to medical treatment, never a replacement for it. (5 studies in our library, 2 in people)
• L-carnitineemerging -- Studied in the same trial. Carnitine acts as a peripheral antagonist of thyroid hormone action -- a genuinely unusual and specific mechanism, and one of the few places carnitine has a thyroid rationale. (1 studies in our library, 1 in people)
• ⛔ Iodine -- to avoid, not to addcontested -- 8 rows. In this pattern iodine is the substrate for a gland already producing too much. Listed here so the page says the opposite of what a supplement aisle would. (8 studies in our library, 2 in people)
• ⚠️ Medical treatment is the interventionsolid -- Antithyroid medication, radioiodine or surgery. Nothing in this library substitutes for that, and the page should not imply otherwise. (30 studies in our library, 18 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• None attributable to the protein itself. Thyroglobulin is the storage protein the thyroid makes hormone from, and a raised level reflects thyroid tissue mass or inflammation.
• Raised in goitre, in thyroiditis, and after any thyroid injury.

What people often feel when it runs low

• No symptoms.

Patterns it travels in

• ⚠️ THYROGLOBULIN'S MAIN USE IS AS A TUMOUR MARKER AFTER THYROID CANCER TREATMENT, not as a general wellness measurement. Once the thyroid has been removed, any detectable thyroglobulin signals remaining tissue. In someone with an intact thyroid it means very little.
• THYROGLOBULIN IS UNINTERPRETABLE IF THYROGLOBULIN ANTIBODIES ARE POSITIVE -- the antibodies interfere with the assay and make the result falsely low. The two must ALWAYS be measured together, and this is one of the strictest pairing rules in the whole library.
• THYROGLOBULIN LOW + goitre can indicate a synthesis defect; low thyroglobulin is also used to distinguish causes of neonatal hypothyroidism.
• ⛔ DO NOT ORDER THIS AS PART OF A WELLNESS PANEL. It generates confusion without answering anything a TSH, free T4, free T3 and antibodies have not answered better.

Ingredients with evidence in our library

• ⚠️ Not a nutrition target, and 10 rows in our library reflect that.mixed -- Thyroglobulin is a monitoring test in a cancer pathway. No supplement claim belongs on this marker, and the useful nutrient evidence sits under TSH, free T3 and thyroid antibodies. (10 studies in our library, 4 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs low

• ⚠️ IN A THYROID PANEL, FERRITIN IS NOT AN OPTIONAL EXTRA. Thyroid peroxidase -- the enzyme that builds thyroid hormone -- is a HAEM enzyme, so it cannot work without iron. Iron deficiency both causes thyroid symptoms and blunts the response to thyroid replacement.
• For the full symptom picture in both directions, read the main iron/ferritin entry -- it is the same measurement, and repeating it here would only risk the two drifting apart.

Patterns it travels in

• FERRITIN LOW + TSH HIGH is the pair this entry exists for. Our library holds iron and ferritin deficiency measured directly in women with hypothyroidism and chronic lymphocytic thyroiditis (7 rows, 3 human).
• FERRITIN LOW + STILL SYMPTOMATIC ON LEVOTHYROXINE -- correcting the iron often does what a dose increase was being asked to do.
• ⚠️ FERRITIN IS AN ACUTE-PHASE PROTEIN. In autoimmune thyroid disease, where inflammation is present, ferritin can read falsely normal. Read it against hs-CRP, and use transferrin saturation when they conflict.
• FERRITIN LOW + TPO ANTIBODIES POSITIVE -- autoimmune thyroid disease frequently coexists with autoimmune gastritis and coeliac disease, both of which impair iron absorption. One cause, several findings.
• A FERRITIN IN THE TEENS OR TWENTIES with thyroid symptoms deserves correcting even though many laboratories call it normal -- the functional threshold for symptoms is well above the anaemia threshold.

Ingredients with evidence in our library

• Iron bisglycinate with vitamin C, dosed alternate-daysolid -- A dose raises hepcidin for about 24 hours and blocks the next one, so alternate-day single doses absorb better than daily split doses and cause fewer gut side effects. Vitamin C multiplies non-haem absorption. (100 studies in our library, 23 in people)
• Haem iron from meat, fish and liversolid -- Absorbed by a different pathway, largely immune to phytate and polyphenol inhibition. (1527 studies in our library, 371 in people)
• ⚠️ Separate iron from levothyroxine by at least four hourssolid -- Iron binds levothyroxine in the gut and blocks its absorption. This is a timing instruction that costs nothing and is very often not given. (3 studies in our library, 2 in people)
• ⚠️ And find the causesolid -- Unexplained iron deficiency needs a reason -- coeliac disease, heavy periods, or in any man or postmenopausal woman, GI blood loss until proven otherwise. That is a doctor's question, not a supplement's. (2486 studies in our library, 1350 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs low

• ⚠️ IN A THYROID PANEL, ZINC IS A CONVERSION COFACTOR. It is required for deiodinase activity -- the step that turns storage T4 into active T3 -- and for the thyroid hormone receptor to bind. Deficiency produces hypothyroid symptoms with a normal TSH.
• For the full symptom picture in both directions, read the main zinc entry -- it is the same measurement, and repeating it here would only risk the two drifting apart.

Patterns it travels in

• ZINC LOW + FREE T4 NORMAL + FREE T3 LOW is a conversion problem, and zinc is one of the three cofactors for that step alongside selenium and iron.
• ZINC + SELENIUM TOGETHER -- our library holds them studied jointly in subclinical hypothyroidism with both mechanistic and clinical evidence (9 rows on TSH, 5 human). They are not two separate questions.
• IODINE + SELENIUM + ZINC -- our library holds a study assessing their JOINT impact on third-trimester thyroid function. Correcting one without the others frequently fails.
• ⚠️ SERUM ZINC FALLS WITH INFLAMMATION and with a recent meal. Draw it fasting and in the morning, and read it against hs-CRP and albumin -- in autoimmune thyroid disease all three caveats apply at once.
• ⚠️ ZINC ALSO REDUCES LEVOTHYROXINE ABSORPTION -- separate them by four hours.

Ingredients with evidence in our library

• Zinc picolinate, citrate or bisglycinatesolid -- Studied alongside selenium in subclinical hypothyroidism. Oxide absorbs poorly. ⚠️ Never long-term at high dose without copper -- roughly 1 mg copper per 15 mg zinc. (2123 studies in our library, 444 in people)
• Oysters, red meat, and reducing phytatesolid -- Oysters carry more zinc per gram than any other food. Soaking, sprouting, fermenting and sourdough leavening degrade the phytate that blocks absorption from grains and legumes. (2298 studies in our library, 1096 in people)
• Selenium, as the partnersolid -- 261 rows carry both tags, 72 human. They act in the same oxidoreductive system and deficiency of both together is commoner than either alone. (261 studies in our library, 72 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Excess risks hypercalcaemia and kidney stones -- read the main vitamin D entry.

What people often feel when it runs low

• In a thyroid panel: vitamin D status is consistently LOWER in autoimmune thyroid disease, and treatment has moved both function and autoimmunity markers in our library's rows.
• The general deficiency picture -- fatigue, aching bones and muscles, low mood worse in winter, frequent illness, hair loss -- overlaps almost entirely with hypothyroid symptoms, which is precisely why both belong on the same panel.

Patterns it travels in

• VITAMIN D LOW + TPO ANTIBODIES POSITIVE is the pairing this entry exists for -- a consistent association, and our library holds vitamin D treatment moving thyroid function and autoimmunity markers together (6 rows, 3 human).
• VITAMIN D LOW + MAGNESIUM LOW -- both hydroxylation steps that activate vitamin D are magnesium-dependent. A level that will not rise on a good dose is usually a magnesium question.
• THE SYMPTOM OVERLAP IS THE PRACTICAL POINT: fatigue, low mood, aching and hair loss belong to both deficiency and hypothyroidism. Correcting vitamin D sometimes resolves what was being attributed to an inadequate thyroid dose.
• VITAMIN D LOW + COELIAC DISEASE -- worth checking in autoimmune thyroid disease, since malabsorption explains both.
• ⚠️ FAT-SOLUBLE -- taken without fat in the meal, much of the dose is wasted. And obesity sequesters it, so a higher dose is often needed for the same blood level.

Ingredients with evidence in our library

• Vitamin D3 with a fat-containing mealsolid -- 795 rows, 345 human across the library -- the second-largest human evidence base we hold. D3 raises and maintains 25(OH)D more effectively than D2. Meta-analyses show reduced thyroid antibody titres especially in those starting deficient. (795 studies in our library, 345 in people)
• Magnesium, as the enabling cofactorsolid -- Required for both activation steps. Correcting magnesium is often what unblocks a stubborn vitamin D level -- and magnesium has its own association with thyroid antibodies. (828 studies in our library, 450 in people)
• Selenium, as the partner with the stronger antibody evidencesolid -- Where the goal is lowering antibody titres, selenium's evidence (31 rows, 17 human, multiple RCTs) is stronger than vitamin D's. Both are worth correcting; honest ordering puts selenium first. (31 studies in our library, 17 in people)
• Sunlight, within the limitssolid -- Skin synthesis is the dominant natural source, limited by latitude, season, skin tone, age, glass and sunscreen. Above roughly 37 degrees latitude, winter sun is too weak regardless of exposure time. (819 studies in our library, 345 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs low

• ⚠️ IN A THYROID PANEL, VITAMIN A IS REQUIRED FOR THE THYROID HORMONE RECEPTOR TO WORK -- the receptor pairs with the retinoid X receptor to switch genes on. Adequate hormone with inadequate vitamin A means the signal arrives and is not read.
• For the full symptom picture in both directions, read the main vitamin A entry -- it is the same measurement, and repeating it here would only risk the two drifting apart.

Patterns it travels in

• VITAMIN A LOW + ZINC LOW -- zinc is needed to make retinol-binding protein, so vitamin A cannot leave the liver without it. A vitamin A deficiency that will not correct is often a zinc deficiency, and 110 rows in our library carry both tags.
• VITAMIN A + IODINE -- deficiency of vitamin A worsens the thyroid consequences of iodine deficiency; the two interact in populations where both are common.
• ZINC + VITAMIN A + MAGNESIUM co-supplemented is a real study design in our library, with thyroid measures among the outcomes (2 rows on TSH, both human).
• VITAMIN A + FERRITIN -- vitamin A mobilises iron from stores, which matters here because iron is itself a thyroid cofactor. 20 rows, 16 of them human.
• ⚠️ PREFORMED RETINOL HAS REAL TOXICITY RISK, including in pregnancy -- read the retinol entry for the doses. Beta-carotene does not carry that risk, but converts at a variable and self-limiting rate.

Ingredients with evidence in our library

• Liver, egg yolks, full-fat dairy (preformed retinol)solid -- 194 rows, 45 human. Directly usable with no conversion step. ⚠️ Also the form carrying the toxicity and pregnancy risk, so dose deserves attention. (194 studies in our library, 45 in people)
• Zinc, as the mobilisation partnersolid -- 110 rows, 45 human. Required for retinol-binding protein -- without it the liver stores stay locked. (110 studies in our library, 45 in people)
• Beta-carotene from orange and dark-green producemixed -- The safer route for adequacy. ⚠️ Common BCMO1 variants substantially reduce conversion, which is why some people eating plenty of orange vegetables still run low. And per ATBC and CARET, current or former heavy smokers should not take high-dose beta-carotene SUPPLEMENTS -- the food is not the problem. (194 studies in our library, 45 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• No established concern from food. High supplemental doses can cause nausea and headache.

What people often feel when it runs low

• Tyrosine is the amino acid backbone that thyroid hormone is built on -- iodine is attached to tyrosine residues to make T3 and T4.
• ⚠️ TRUE TYROSINE DEFICIENCY IS RARE IN ANYONE EATING ADEQUATE PROTEIN. The body also makes tyrosine from phenylalanine, so shortfall essentially requires very low protein intake or the genetic condition PKU. It is not the bottleneck in most thyroid problems, and selling it as one overstates the case.
• Where intake is genuinely low: low mood, low drive and poor stress tolerance -- tyrosine is also the precursor for dopamine, adrenaline and noradrenaline, which is where most of its real evidence sits.

Patterns it travels in

• TYROSINE + IODINE + SELENIUM + IRON is the hormone-synthesis chain: tyrosine is the scaffold, iodine the substrate, thyroid peroxidase (a haem/iron enzyme) does the attaching, and selenium-dependent deiodinases activate the result. A gap anywhere breaks the chain -- and iodine, iron and selenium are all far commoner gaps than tyrosine.
• TYROSINE'S BETTER-EVIDENCED ROLE IS CATECHOLAMINE SYNTHESIS -- performance under acute stress, sleep deprivation and cold. That literature is stronger than its thyroid literature.
• ⚠️ ANYONE WITH PKU MUST NOT FOLLOW GENERAL PHENYLALANINE/TYROSINE ADVICE.
• ⚠️ THE LIBRARY COUNT ON THIS MARKER IS INFLATED BY A HOMONYM: many of the 126 tyrosine-tagged rows concern TYROSINE KINASE inhibitors -- a class of cancer drugs, an entirely different subject that merely shares the word. The real amino-acid evidence base here is much smaller than the number suggests, and saying so is more useful than quoting it.

Ingredients with evidence in our library

• Dietary proteinsolid -- Tyrosine comes from ordinary protein intake and from phenylalanine conversion. In anyone eating adequate protein this is a solved problem, and effort belongs on iodine, iron and selenium instead. (126 studies in our library, 26 in people)
• ⚠️ L-tyrosine supplementation -- read the count carefullycontested -- The 126-row count is contaminated by tyrosine kinase inhibitor research. What genuine human evidence exists is largely about cognitive performance under acute stressors, NOT about raising thyroid hormone in people with adequate protein intake. Presenting it as a thyroid supplement overstates what the library holds. (126 studies in our library, 26 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs low

• ⚠️ IN A THYROID PANEL, MAGNESIUM IS THE QUIETEST ENTRY AND HAS THE THINNEST DIRECT EVIDENCE -- which is worth stating rather than inflating. Its established thyroid link is an association: our library holds severely low serum magnesium associated with positive anti-thyroglobulin antibodies.
• For the full symptom picture in both directions, read the main magnesium entry -- it is the same measurement, and repeating it here would only risk the two drifting apart.

Patterns it travels in

• MAGNESIUM SEVERELY LOW + THYROGLOBULIN ANTIBODIES POSITIVE -- the specific association our library holds (1 row, human). An association and a reason to check, not a demonstrated lever.
• MAGNESIUM + VITAMIN D -- the stronger and better-evidenced link, and it matters here because vitamin D has real evidence in thyroid autoimmunity. Vitamin D activation is magnesium-dependent, so a vitamin D level that will not rise is often a magnesium problem.
• MAGNESIUM LOW + THE HYPOTHYROID SYMPTOM OVERLAP -- fatigue, cramps, poor sleep, low mood and constipation belong to both. Correcting magnesium can resolve symptoms that were being attributed to the thyroid.
• MAGNESIUM + ZINC + VITAMIN A -- our library holds a randomised study of these three co-supplemented, with thyroid measures among the outcomes.
• ⚠️ SERUM MAGNESIUM IS A POOR TEST -- under 1% of body magnesium is in serum, and the body defends that number from bone and muscle. RBC magnesium is better; symptoms are often better still.

Ingredients with evidence in our library

• Magnesium glycinate, malate or citratesolid -- 775 rows, 241 human across the library -- a large body of human evidence, though little of it with thyroid endpoints specifically. Oxide is poorly absorbed and works mainly as a laxative. (775 studies in our library, 241 in people)
• Leafy greens, pumpkin seeds, cacao, legumes, mineral watersolid -- The food route. Our library holds a specific finding worth knowing: very low-mineral water is associated with worse cardiovascular measures and higher homocysteine -- what is absent from drinking water counts as intake too. (828 studies in our library, 450 in people)
• ⚠️ Honest sizingemerging -- Magnesium's thyroid-specific evidence is one association, not a trial. Its value here is real but indirect -- enabling vitamin D, and resolving the symptom overlap. Selenium, iodine, iron and zinc are the cofactors with direct thyroid evidence. (1 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Joint pain and stiffness WORSE IN THE MORNING and easing with movement -- the opposite of mechanical wear. That single distinction is the most useful question there is here.
• Symmetrical small-joint swelling; prolonged morning stiffness over 30-60 minutes.
• Rashes across the cheeks or triggered by sun; mouth ulcers; hair loss; dry eyes and dry mouth.
• Raynaud's -- fingers going white then blue in the cold.
• Unexplained low-grade fevers; fatigue that is disproportionate and unrefreshing.
• ⚠️ ROUGHLY 1 IN 5 HEALTHY ADULTS TESTS POSITIVE AT LOW TITRE, more in older women. On its own a positive ANA means very little, and it has caused an enormous amount of unnecessary fear.

What people often feel when it runs low

• Negative is expected and carries no symptoms.

Patterns it travels in

• ⛔ NEVER ORDER ANA WITHOUT SYMPTOMS. A positive in an asymptomatic person generates anxiety, more tests and no benefit.
• TITRE AND PATTERN BOTH MATTER. 1:40 is common and usually meaningless; 1:640 with symptoms is a different conversation. The pattern -- homogeneous, speckled, nucleolar, centromere -- points toward different conditions and guides which ENA antibodies to check next.
• ANA POSITIVE + SYMPTOMS = order the specific ENA panel (anti-dsDNA, anti-Sm, SSA/Ro, SSB/La, Scl-70, Jo-1, centromere). ANA positive + no symptoms = stop.
• ANA POSITIVE + LOW COMPLEMENT C3/C4 + PROTEINURIA is the active lupus picture and needs a rheumatologist promptly.
• ANA POSITIVE + TPO ANTIBODIES POSITIVE -- autoimmunity clusters; thyroid is the commonest companion.
• ⚠️ SOME MEDICATIONS INDUCE A POSITIVE ANA (hydralazine, procainamide, minocycline, anti-TNF agents). Ask before investigating.

Ingredients with evidence in our library

• ⛔ No food reverses an already-positive ANA -- our own panel file states this outrightsolid -- `Panels/Autoimmune.md` says no food reverses a positive ANA, RF, anti-CCP, or any ENA-panel antibody, and our food-to-marker matrix tags it [SOLID that no lever exists]. Someone with a positive result deserves to know where the leverage genuinely is -- on inflammation and symptoms, not on the titre. (78 studies in our library, 40 in people)
• Vitamin D -- the VITAL result, and it is about PREVENTIONemerging -- VITAL (25,871 participants) found vitamin D reduced INCIDENT autoimmune disease diagnoses by 22% over about 5.3 years. That is population-level prevention, not evidence that it lowers an existing titre. Our matrix tags it [EMERGING, population-level] and the distinction is the point. (795 studies in our library, 345 in people)
• A supervised fast then gluten-free vegan then lacto-vegetarian eating -- for RA specificallysolid -- One of very few dietary interventions in the whole Labs folder with a positive, replicated RCT in established autoimmune disease: significant improvement in tender and swollen joints, ESR and CRP, sustained to one year. Modest trial base, and real. (1 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Non-specific by design: fatigue, malaise, aching, low-grade fever, morning stiffness.
• ESR rises and falls SLOWLY -- over weeks -- where CRP moves in a day or two. That makes ESR better for tracking a chronic process and worse for anything acute.
• ⚠️ ESR RISES WITH AGE, WITH ANAEMIA, WITH PREGNANCY AND WITH BEING FEMALE, entirely independently of inflammation. An age-adjusted range is essential; the classic rule of thumb is age divided by two for men, age plus ten divided by two for women.

What people often feel when it runs low

• No concern. Very low values occasionally accompany polycythaemia or marked abnormalities of red cell shape.

Patterns it travels in

• ESR + hs-CRP TOGETHER, because they disagree usefully. CRP rises and falls fast; ESR is slow and is influenced by red cell factors. ESR HIGH + CRP NORMAL often means anaemia, a paraprotein, or a slow-burning process rather than active inflammation.
• ESR HIGH + HAEMOGLOBIN LOW -- check the anaemia before concluding inflammation, since the anaemia alone raises ESR.
• ESR VERY HIGH (over ~100) + age over 50 + new headache, scalp tenderness or jaw claudication ⚠️ needs urgent assessment for giant cell arteritis. This is one of the few genuinely time-critical patterns in the whole library and belongs on the page for that reason.
• ESR + CRP both raised + morning stiffness over an hour + symmetrical small joints is the inflammatory-arthritis picture worth pursuing.

Ingredients with evidence in our library

• ⚠️ No nutrient reliably and specifically lowers ESR -- and our brain says so plainly.contested -- `Panels/Autoimmune.md`: no nutrient reliably lowers ESR outside of correcting an underlying driver -- anaemia, obesity, or the active inflammation itself. The vitamin D, curcumin, omega-3 and magnesium evidence against inflammatory markers was generated almost entirely using CRP as the endpoint, NOT ESR. Any ESR-lowering claim is extrapolated rather than directly proven, and should be labelled that way. (83 studies in our library, 30 in people)
• Correcting anaemia -- the most direct lever, and it is not anti-inflammatorysolid -- Because anaemia raises ESR mechanically, correcting iron or B12 deficiency lowers the number without touching inflammation at all. That is worth knowing precisely so the fall is not misread as the disease improving. (1102 studies in our library, 601 in people)
• A supervised fast followed by gluten-free vegan then lacto-vegetarian eatingsolid -- The rheumatoid arthritis trial our brain rates highest -- significant improvement in tender and swollen joints, ESR AND CRP, sustained to one year. This is one of the very few dietary interventions with ESR itself as a measured, improved outcome. (1 studies in our library, 1 in people)
• The Mediterranean pattern, curcumin, omega-3 and vitamin Demerging -- Real evidence against inflammatory markers generally -- read the hs-CRP entry for it. Listed here as extrapolation, clearly labelled, rather than restated as if ESR had been the endpoint. (509 studies in our library, 144 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• In an autoimmune panel, hs-CRP is the activity gauge rather than the diagnosis: deep unrefreshing fatigue, migrating aching, morning stiffness, low mood and anhedonia with no situational cause.
• Poor recovery from ordinary exertion; getting ill more easily.
• ⚠️ A SINGLE HIGH READING USUALLY MEANS A RECENT INFECTION, INJURY OR HARD TRAINING SESSION. Repeat when well before drawing conclusions.

What people often feel when it runs low

• Low is the desired direction.

Patterns it travels in

• ⚠️ THE AUTOIMMUNE-SPECIFIC CATCH: IN LUPUS, CRP IS OFTEN UNREMARKABLE DURING A FLARE while ESR and complement move. That dissociation is itself informative and it catches people out -- do not read a normal CRP as quiet disease in lupus.
• hs-CRP + ESR together, because they disagree usefully -- CRP fast, ESR slow and influenced by red cell factors.
• hs-CRP HIGH + FERRITIN HIGH + IRON SATURATION LOW -- ferritin is an acute-phase protein, so inflammation can make an iron-deficient person look replete. Iron given on that misreading makes things worse.
• hs-CRP HIGH + ALBUMIN LOW is the acute-phase response from both ends.
• hs-CRP NORMAL DOES NOT MEAN NO INFLAMMATION -- localised gut, joint or oral inflammation can be substantial with a normal systemic value.

Ingredients with evidence in our library

• Mediterranean-pattern eatingsolid -- Our matrix calls it the most reliable food-level lever on hs-CRP of anything in the file [EMERGING, but consistently replicated] -- olive oil, fatty fish, vegetables, nuts. (509 studies in our library, 144 in people)
• Berries and polyphenol-rich producesolid -- The MaPLE RCT (51 adults 60+) found an 8-week polyphenol-rich diet significantly lowered serum and faecal calprotectin and improved barrier markers alongside inflammatory signals [SOLID for that trial]. (81 studies in our library, 19 in people)
• Vitamin Dsolid -- 9 rows, 8 human -- the most human-weighted association on this marker in our library. Read causally with caution: inflammation itself lowers measured 25(OH)D. (9 studies in our library, 8 in people)
• Curcuminsolid -- Pooled meta-analyses show CRP reduction, though poor natural bioavailability makes formulation matter [EMERGING]. Also the single RCT on complement C3 in lupus nephritis. (4 studies in our library, 4 in people)
• Omega-3, selenium, zinc and probioticssolid -- Each with human trial evidence against inflammatory markers -- read the baseline hs-CRP entry for the full set and counts. (509 studies in our library, 144 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• C3 and C4 are acute-phase proteins and rise with ordinary inflammation and infection. A high value is rarely the interesting finding.

What people often feel when it runs low

• Low complement means it is being CONSUMED by active immune-complex disease -- most characteristically active lupus, and especially lupus nephritis.
• Symptoms are the underlying disease's: rashes (including the malar rash), joint pain, mouth ulcers, hair loss, fatigue, fevers, and -- critically -- kidney involvement, which is often silent.
• ⚠️ FALLING C3 AND C4 CAN PRECEDE A CLINICAL FLARE, which is why they are tracked serially in lupus rather than measured once.
• Persistently low complement with recurrent bacterial infections may instead indicate an inherited deficiency.

Patterns it travels in

• C3 AND C4 LOW + ANTI-dsDNA RISING + PROTEINURIA is the lupus flare pattern, and the one where the urinalysis matters most. ⚠️ Low complement always needs clinical correlation and specifically a check for kidney involvement -- our own `Panels/Autoimmune.md` states this as a safety caveat.
• C4 LOW ALONE with normal C3 can be an inherited partial C4 deficiency -- common, and not the same as active consumption.
• COMPLEMENT + ESR + hs-CRP together: in lupus specifically, CRP is often unremarkable during a flare while ESR and complement move. That dissociation is itself informative, and it catches people out.
• COMPLEMENT LOW + RECURRENT NEISSERIAL INFECTIONS points at a terminal-pathway deficiency and belongs to immunology.

Ingredients with evidence in our library

• Curcumin -- a real RCT, and precisely boundedemerging -- A randomised trial in lupus nephritis (44 subjects, 1,000 mg/day for 12 weeks ADDED to standard immunotherapy) found significantly improved complement C3 and reduced serum NLRP3 inflammasome activity versus standard therapy alone (cite: European Journal of Nutrition, 2024). ⚠️ Small, short, and specific to lupus nephritis on top of standard treatment -- our brain is explicit that this is NOT a general 'complement booster'. (1 studies in our library, 1 in people)
• Vitamin Dmixed -- A 2022 meta-analysis of 6 RCTs (276 SLE patients) found supplementation improved C3/C4 alongside reduced SLEDAI disease-activity scores in some pooled analyses -- though effects on anti-dsDNA positivity specifically were inconsistent across different meta-analyses of the same literature. Tagged [EMERGING, mixed] in our own panel file, and repeated at that weight. (9 studies in our library, 5 in people)
• ⛔ Nothing normalises complement independent of treating the diseasesolid -- `Panels/Autoimmune.md`: there is no dietary or supplement intervention proven to normalise complement levels independent of treating the underlying disease activity. Curcumin and vitamin D are reasonable adjuncts to discuss WITH a rheumatologist, never substitutes for standard lupus management. Treat any claim of a supplement 'restoring' complement with scepticism. (53 studies in our library, 16 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Symmetrical small-joint pain and swelling with morning stiffness over an hour, easing with movement.
• Fatigue; sometimes rheumatoid nodules over pressure points.
• ⚠️ RHEUMATOID FACTOR IS POSITIVE IN A GREAT MANY THINGS THAT ARE NOT RHEUMATOID ARTHRITIS -- hepatitis C, chronic infections, Sjogren's, and a fair share of healthy older people. Specificity falls with age.
• ANTI-CCP IS FAR MORE SPECIFIC and is the better test when the question is genuinely rheumatoid.

What people often feel when it runs low

• Negative does not exclude seronegative rheumatoid arthritis, which is a real and reasonably common presentation.

Patterns it travels in

• RF + ANTI-CCP TOGETHER. Both positive with symptoms is a strong signal; RF alone is weak. If only one can be ordered, order anti-CCP.
• RF POSITIVE + hs-CRP/ESR RAISED + symmetrical small-joint swelling should reach a rheumatologist quickly -- early treatment materially changes the joint damage that follows.
• RF POSITIVE + DRY EYES AND MOUTH + SSA/Ro points at Sjogren's rather than RA.
• ⚠️ RF POSITIVE + no symptoms in an older person is common and usually means nothing.
• RF + SMOKING -- the strongest known environmental risk factor for seropositive RA, and the interaction with the shared-epitope genotype is one of the clearest gene-environment findings in rheumatology.

Ingredients with evidence in our library

• ⛔ No food reverses a positive rheumatoid factorsolid -- Stated in our own panel file alongside ANA and anti-CCP. The leverage is on inflammation, symptoms and disease activity -- not on the antibody. (78 studies in our library, 40 in people)
• Omega-3 -- strongest at the at-risk stagemixed -- The SERA cohort found omega-3 biomarkers and supplement use associated with lower prevalence of anti-CCP positivity and lower progression to inflammatory arthritis in at-risk individuals (cite: Gan RW et al., Ann Rheum Dis 2017, PMC5371398). ⚠️ In ESTABLISHED disease a 2024 meta-analysis of 18 RCTs (1,018 patients) found mixed effects and no consistent antibody-lowering. (355 studies in our library, 205 in people)
• The supervised fast and plant-based sequencesolid -- Improved tender and swollen joint counts, ESR and CRP, sustained to one year. Our brain's highest-rated dietary intervention for established RA. (1 studies in our library, 1 in people)
• Stopping smoking, and dental caresolid -- Smoking is the largest modifiable risk factor. Periodontal disease is an actively studied initiating mechanism via bacterial citrullination -- low-cost and reasonable to address. (78 studies in our library, 40 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Symmetrical small-joint pain and swelling -- both hands, both wrists -- with morning stiffness lasting more than about an hour and easing with movement.
• Fatigue that is disproportionate and unrefreshing.
• ⚠️ ANTI-CCP CAN BE POSITIVE YEARS BEFORE ANY JOINT SYMPTOM APPEARS. That pre-clinical window is the most interesting thing about this marker, and it is where the only nutrition evidence lives.
• Anti-CCP is far MORE SPECIFIC for rheumatoid arthritis than rheumatoid factor, and predicts more erosive disease -- which is why it is the better test when the question is genuinely RA.

What people often feel when it runs low

• Negative is expected; a negative anti-CCP does not exclude seronegative rheumatoid arthritis.

Patterns it travels in

• ANTI-CCP POSITIVE + RF POSITIVE + hs-CRP/ESR RAISED + symmetrical small-joint swelling is the picture that should reach a rheumatologist quickly -- early treatment materially changes the joint damage that follows.
• ANTI-CCP POSITIVE + NO SYMPTOMS + family history is a meaningful risk signal worth discussing with a rheumatologist for MONITORING. ⚠️ Our own panel file is explicit that it is not something to try to 'treat away' with supplements alone.
• ANTI-CCP + SMOKING -- smoking is the strongest known environmental risk factor for anti-CCP-positive RA, and the interaction with the shared-epitope genotype is one of the clearest gene-environment findings in rheumatology. Stopping is the single most evidence-backed thing anyone can do here.
• ANTI-CCP + PERIODONTAL DISEASE -- citrullination by oral bacteria is a plausible and actively studied initiating mechanism. Dental care is a reasonable, low-cost part of the conversation.

Ingredients with evidence in our library

• Omega-3 -- and the finding is specifically about the at-risk stageemerging -- The SERA cohort found omega-3 biomarkers and supplement use associated with LOWER prevalence of anti-CCP positivity and lower rates of progression to inflammatory arthritis in anti-CCP-positive at-risk individuals, with docosapentaenoic acid specifically linked to reduced progression risk (cite: Gan RW et al., Annals of the Rheumatic Diseases 2017, PMC5371398). This is prevention-stage evidence, and it is genuinely interesting. (355 studies in our library, 205 in people)
• ⚠️ Omega-3 in ESTABLISHED disease -- a different and weaker storycontested -- [CONTESTED]. A 2024 meta-analysis of 18 RCTs (1,018 RA patients on standard therapy) found MIXED effects on inflammation and disease activity, and no consistent antibody-lowering effect (cite: Clinical Rheumatology 2024). The direction of that difference -- stronger before disease, weaker after -- is the honest headline and is usually reversed in marketing. (355 studies in our library, 205 in people)
• Stopping smokingsolid -- The strongest known modifiable risk factor for anti-CCP-positive rheumatoid arthritis. Larger than any supplement effect in this entry, and free. (78 studies in our library, 40 in people)
• Vitamin D sufficiencyemerging -- Alongside omega-3, the most evidence-backed lever our panel file names -- and again strongest in prevention-stage and at-risk populations rather than in reversing established disease. VITAL's 22% reduction in incident autoimmune diagnoses is the population-level version of this. (795 studies in our library, 345 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• HIGH IgG polyclonally accompanies chronic infection, chronic inflammation and liver disease. A monoclonal rise is a different matter and needs haematology.
• HIGH IgA can accompany liver disease and IgA nephropathy.

What people often feel when it runs low

• LOW IgG: recurrent bacterial infections -- chest, sinus, ear -- that are frequent, severe, or slow to clear.
• LOW IgA (selective IgA deficiency, ~1 in 500, the commonest primary immunodeficiency): often NO symptoms at all; some have recurrent respiratory or gut infections, and there is an association with coeliac disease and other autoimmunity.
• ⚠️ THE CLINICALLY CRITICAL CONSEQUENCE OF LOW IgA IS A FALSELY NEGATIVE COELIAC SEROLOGY, because the standard test is an IgA antibody. This is why total IgA belongs on every coeliac request.

Patterns it travels in

• ⛔ TOTAL IgA BEFORE ANY COELIAC SEROLOGY. Selective IgA deficiency is commoner in coeliac disease, and a negative tTG-IgA in that person is not a true negative. Use IgG-based tests instead.
• LOW IgG + LOW IgA + LOW IgM together with recurrent infections is common variable immunodeficiency and needs immunology -- not a supplement.
• IMMUNOGLOBULINS + LYMPHOCYTE COUNT together give a fuller picture of humoral competence.
• ⚠️ MEDICATIONS LOWER IgG -- rituximab, long-term steroids, some antiepileptics. Ask before investigating.
• LOW IgA + AUTOIMMUNITY -- the association is real, which is why this sits in an autoimmune panel at all.

Ingredients with evidence in our library

• ⚠️ Immunoglobulin levels are not a nutrition targetsolid -- A genuine antibody deficiency is an immunology diagnosis with a management pathway -- immunoglobulin replacement where indicated. No supplement corrects it, and framing it as correctable would delay proper assessment.
• Adequate protein, zinc and vitamin A -- in deficiency onlyemerging -- Support normal antibody production where intake is genuinely inadequate. Our matrix is careful: not proven to raise levels further in a replete adult. (22 studies in our library, 6 in people)
• The actionable finding here is usually the coeliac onesolid -- Discovering selective IgA deficiency changes how coeliac disease is tested for, and coeliac disease has a definitive treatment. That is what makes this measurement worth its place on the panel. (78 studies in our library, 40 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• ⚠️ HIGH IgG4 raises IgG4-related disease -- a fibro-inflammatory condition affecting pancreas, salivary glands, orbits, retroperitoneum and other tissues, and one that is frequently missed for years because it mimics other things.

What people often feel when it runs low

• Recurrent bacterial respiratory infections -- particularly with low IgG2, which handles polysaccharide-encapsulated organisms -- even when TOTAL IgG reads normal.
• ⚠️ THAT IS THE ENTIRE REASON THIS TEST EXISTS: a normal total IgG can hide a subclass deficiency, because IgG1 makes up most of the total and can mask a low IgG2, IgG3 or IgG4.

Patterns it travels in

• SUBCLASSES ONLY AFTER TOTAL IMMUNOGLOBULINS, and only where recurrent infections justify the question. Ordering them speculatively produces borderline numbers with no clinical anchor.
• LOW SUBCLASS + POOR VACCINE RESPONSE is what makes a low number meaningful -- specific antibody responses to pneumococcal and tetanus vaccination test whether the immune system can actually do the job. The functional test matters more than the level.
• HIGH IgG4 + organ involvement -- pancreatitis, sialadenitis, orbital masses, retroperitoneal fibrosis -- needs specialist assessment.
• ⚠️ SUBCLASS LEVELS VARY WITH AGE, and children's reference ranges differ substantially from adults'.
• ⚠️ IgG4 IN A FOOD PANEL IS AN ENTIRELY DIFFERENT USE and is not validated -- the EAACI task force concluded IgG4 testing against foods 'is not recommended as a diagnostic tool'. Do not confuse serum IgG4 subclass with food-specific IgG4.

Ingredients with evidence in our library

• ⚠️ Not a nutrition targetsolid -- A genuine subclass deficiency with recurrent infection is an immunology question. No dietary intervention raises a subclass, and implying otherwise would delay proper assessment of someone who is genuinely getting ill.
• Vaccination and infection managementsolid -- The evidence-based response -- ensuring vaccination is current, and prompt treatment of infections. Where deficiency is confirmed, prophylactic antibiotics or immunoglobulin replacement are the clinical options.
• Correcting genuine nutrient deficiency, where presentemerging -- Zinc, vitamin A and adequate protein support normal antibody production in deficiency -- worth checking in anyone with recurrent infection, and honestly framed as correcting a deficit rather than boosting a normal level. (22 studies in our library, 6 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Hay fever, allergic rhinitis, itchy watery eyes.
• Asthma -- wheeze, cough, chest tightness, particularly with a known trigger.
• Eczema, hives, and swelling of lips or eyelids.
• Immediate reactions to specific foods -- within minutes, involving skin, breathing or gut.
• ⚠️ SENSITISATION IS NOT ALLERGY. A positive allergen-specific IgE means the immune system recognises that protein; it does NOT mean the person reacts to it. Plenty of people have positive IgE to foods they eat happily. The clinical history decides, not the panel.

What people often feel when it runs low

• Normal, and a normal total IgE does not exclude allergy.

Patterns it travels in

• ⛔ NEVER ELIMINATE FOODS ON A POSITIVE IgE PANEL ALONE. Unnecessary elimination narrows the diet, costs nutrients, and in children can actually CAUSE allergy by removing tolerance-building exposure. The history plus, where needed, supervised challenge is what decides.
• TOTAL IgE VERY HIGH + eczema + recurrent infections in a child raises rarer immune conditions and needs specialist assessment.
• IgE HIGH + EOSINOPHILS HIGH is the allergic picture confirmed two ways; the same pair with travel history raises parasites instead.
• ⚠️ IgG FOOD PANELS ARE A DIFFERENT TEST AND ARE NOT VALIDATED FOR DIAGNOSING FOOD ALLERGY -- IgG to food is a normal marker of exposure. Our brain flags the IgG food sensitivity entry [CONTESTED] for exactly this reason. Do not conflate the two.

Ingredients with evidence in our library

• ⛔ There is no nutrient supplement with solid evidence for lowering IgE -- and our brain names the trialscontested -- A secondary analysis of the VDKA trial (children with asthma and low vitamin D) tested whether D3 lowered total and allergen-specific IgE: results were mixed and not clearly beneficial (cite: J Allergy Clin Immunol 2021, PMC8655021). A systematic review and meta-analysis of 13 RCTs in asthma found NO significant effect on serum IgE, though it did raise anti-inflammatory IL-10 (cite: PMC10965564). Our panel file's instruction is blunt: don't market vitamin D or any supplement as an 'IgE reducer'. (9 studies in our library, 5 in people)
• Vitamin D sufficiency -- as general immune support, framed as that and no moreemerging -- Reasonable to correct a deficiency on its own merits. Not an IgE intervention, and the distinction is the whole point. (795 studies in our library, 345 in people)
• Standard allergy managementsolid -- Allergen avoidance where a genuine reaction is established, and medical therapy. That is the evidence-based approach, and for food allergy in infancy, early INTRODUCTION rather than avoidance is what the evidence now supports.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• In an autoimmune panel these are here because THYROID AUTOIMMUNITY IS THE COMMONEST AUTOIMMUNE CONDITION THERE IS, and it clusters with everything else on this panel.
• Often silent for years; then the hypothyroid picture -- cold, fatigue, fog, hair thinning, heavy periods -- appearing while TSH still reads normal.
• A personal or family history of coeliac disease, type 1 diabetes, vitiligo or rheumatoid arthritis makes this much more likely.

What people often feel when it runs low

• Negative is the desired result.

Patterns it travels in

• TPO/Tg POSITIVE + ANA POSITIVE -- autoimmunity clusters. Finding one is a reason to check the others, and thyroid is the commonest companion to almost everything on this panel.
• TPO POSITIVE + TSH NORMAL is the earliest actionable finding in the whole autoimmune workup, and where selenium has its best evidence.
• TPO/Tg POSITIVE + FERRITIN LOW + B12 LOW / MMA HIGH is the autoimmune gastritis and coeliac cluster -- one gut lining problem producing several findings.
• ⛔ THYROGLOBULIN ANTIBODIES MUST BE MEASURED WHENEVER THYROGLOBULIN IS -- they interfere with that assay and make it read falsely low.
• ⚠️ A POSITIVE TPO IN PREGNANCY raises miscarriage and postpartum thyroiditis risk and warrants closer TSH monitoring.

Ingredients with evidence in our library

• Seleniumsolid -- The single best-evidenced nutrient-antibody relationship in the entire Labs folder -- 31 rows, 17 human, with meta-analyses of RCTs showing reliable TPOAb and TgAb reduction at 3-6 months, though the effect can fade with long-term use. Two Brazil nuts a day supplies the dose; the safe window is narrow. (31 studies in our library, 17 in people)
• Vitamin Demerging -- Meta-analyses show reduced antibody titres, especially in those starting out deficient [EMERGING]. (6 studies in our library, 3 in people)
• Screening for coeliac diseasesolid -- Common in this group, definitively treatable, and it explains the iron and B12 deficiencies that travel alongside. Check tTG-IgA with total IgA. (78 studies in our library, 40 in people)
• ⚠️ Iodine -- to be careful with here, not enthusiastic aboutcontested -- Excess can trigger or worsen thyroid autoimmunity in susceptible people. The opposite of the supplement-aisle instinct, and correcting selenium comes first. (13 studies in our library, 5 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Classic: diarrhoea, bloating, wind, weight loss, and pale greasy stools.
• ⚠️ MOST ADULTS DIAGNOSED TODAY DO NOT PRESENT THAT WAY. The commoner presentation is iron deficiency that will not correct, fatigue, low bone density, mouth ulcers, headaches, low mood, infertility or recurrent miscarriage, and abnormal liver enzymes -- with no obvious gut symptoms at all.
• Dermatitis herpetiformis -- intensely itchy blistering rash on elbows, knees, buttocks or scalp -- is coeliac disease of the skin and is diagnostic in itself.
• Short stature or delayed puberty in children.

What people often feel when it runs low

• Negative is the expected result -- with the two critical caveats below.

Patterns it travels in

• ⛔ ALWAYS CHECK TOTAL IgA ALONGSIDE tTG-IgA. The standard test is an IgA antibody, and selective IgA deficiency affects roughly 1 in 500 -- and is MORE common in coeliac disease. A 'negative' screen in someone IgA-deficient is not a true negative, and our own `Panels/Autoimmune.md` states this outright. Where IgA is deficient, IgG-based tests (DGP-IgG, tTG-IgG) are the ones to use.
• ⛔ DO NOT START A GLUTEN-FREE DIET BEFORE TESTING IS COMPLETE. Removing gluten normalises antibody levels and causes a false negative, delaying accurate diagnosis -- sometimes by years. This is the single most consequential sequencing error in the whole library, because it is so easy to make with good intentions.
• COELIAC SEROLOGY + FERRITIN LOW + B12 LOW + VITAMIN D LOW + LOW BONE DENSITY is the malabsorption picture, and it is often what leads to the diagnosis rather than gut symptoms.
• COELIAC + THYROID ANTIBODIES + TYPE 1 DIABETES -- autoimmunity clusters, and finding one is a reason to check the others.
• SEROLOGY POSITIVE + BIOPSY is still the confirmation pathway in most adults; very high tTG titres can allow a no-biopsy route in children under some guidelines.

Ingredients with evidence in our library

• Strict gluten elimination -- and this is guideline-level standard of care, not an adjunctsolid -- Our brain puts it precisely: this is one of the few places in integrative nutrition where the DIETARY intervention itself IS the standard of care, full stop. Not a supportive measure, not a trial -- the treatment. Antibodies fall over months and the intestinal lining heals. (78 studies in our library, 40 in people)
• Correcting what the malabsorption costsolid -- Iron, B12, folate, vitamin D, calcium and zinc are all commonly depleted at diagnosis and need measuring and correcting alongside the diet. The diet stops the damage; it does not refill the stores. (1102 studies in our library, 601 in people)
• ⚠️ Bone density deserves checking at diagnosissolid -- Long-standing untreated coeliac disease costs bone, and it is one of the presentations that is silent until a fracture.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• The B12 deficiency picture, arriving slowly: fatigue, breathlessness, tingling and numbness in hands and feet, balance that is worse in the dark, brain fog, memory slipping, low mood, a sore beefy-red tongue.
• Often no gut symptoms at all, despite the cause being in the stomach lining.
• ⚠️ THE NEUROLOGICAL DAMAGE CAN BECOME PERMANENT. This is one of very few markers on the whole panel where delay costs something irreversible.
• Frequently coexists with other autoimmunity -- thyroid especially, and vitiligo.

What people often feel when it runs low

• Negative antibodies are the expected result; they do not exclude other causes of B12 deficiency.

Patterns it travels in

• INTRINSIC FACTOR ANTIBODY POSITIVE + MMA HIGH + B12 LOW-OR-NORMAL is pernicious anaemia. Note MMA rather than serum B12 -- serum B12 can read normal while the cells are functionally deficient.
• PARIETAL CELL ANTIBODY IS SENSITIVE BUT NOT SPECIFIC; INTRINSIC FACTOR ANTIBODY IS SPECIFIC BUT NOT SENSITIVE. Read together, they are far more useful than either alone -- a negative intrinsic factor antibody does not rule it out.
• AUTOIMMUNE GASTRITIS + FERRITIN LOW -- the same atrophic stomach lining loses the acid needed to absorb iron. This is why B12 deficiency and iron deficiency arrive together and why an MCV can look deceptively normal.
• PERNICIOUS ANAEMIA + THYROID ANTIBODIES POSITIVE is the commonest autoimmune pairing here.
• ⚠️ IT RAISES LONG-TERM GASTRIC CANCER AND CARCINOID RISK through chronic atrophic gastritis -- our own panel file is explicit that this needs gastroenterology follow-up, with endoscopic surveillance in some cases, and not simply a B12 supplement.

Ingredients with evidence in our library

• B12 by a route that bypasses intrinsic factor -- and it is a workaround, not a curesolid -- Injection, high-dose oral (which has a small intrinsic-factor-independent absorption pathway), or sublingual. Our panel file is careful about this wording: the autoimmune attack on parietal cells and intrinsic factor is not being treated, only its consequence. (cite: NIH ODS Vitamin B12 Health Professional Fact Sheet) (546 studies in our library, 181 in people)
• Lifelong monitoring, not a coursesolid -- Pernicious anaemia is permanent and needs ongoing B12 monitoring and repletion -- plus gastroenterology follow-up for the gastric cancer risk. A one-off correction is not the treatment. (546 studies in our library, 181 in people)
• Iron, checked alongsidesolid -- The same atrophic gastritis impairs iron absorption. Correcting only the B12 leaves half the problem in place. (2486 studies in our library, 1350 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Bloating and abdominal discomfort that does not track neatly with any one food.
• Fatigue and brain fog after eating.
• Joint aches with no injury; skin flares (eczema, rosacea).
• Food reactions that seem to broaden over time rather than narrow.
• ⚠️ THE HONEST POSITION ON THIS TEST: increased intestinal permeability is a REAL and well-documented phenomenon. Whether the commercially available serum zonulin assay measures it reliably is genuinely disputed -- several published analyses found the widely-used ELISA is not detecting zonulin (pre-haptoglobin-2) but a related protein. The biology is sound; the specific test is not settled.

What people often feel when it runs low

• No symptoms; an intact barrier is the desired state.

Patterns it travels in

• ZONULIN HIGH + HS-CRP HIGH is the mechanism the cross-reference spec predicts end to end: barrier failure lets bacterial endotoxin (LPS) into portal circulation, which drives systemic inflammation. This is the single best-supported gut-to-body pathway there is.
• ZONULIN HIGH + FECAL CALPROTECTIN NORMAL suggests permeability without frank intestinal inflammation -- a different situation from inflammatory bowel disease, and calprotectin is the test that separates them.
• ZONULIN HIGH + CELIAC SEROLOGY POSITIVE -- gluten is a direct and well-documented zonulin trigger in coeliac disease, which is where the whole zonulin story began. Exclude coeliac before anything else.
• ZONULIN HIGH + LOW FECAL SCFAs / LOW DIVERSITY -- butyrate is the primary fuel for colonocytes and directly maintains tight junctions. Low butyrate production is one of the most mechanistically plausible causes of a leaky barrier.
• ⚠️ CONFOUNDERS THAT RAISE PERMEABILITY AND ARE OFTEN MISSED: NSAIDs (reliably and substantially), alcohol, intense endurance exercise especially in heat, acute stress, and any recent gut infection.
• THE LACTULOSE:MANNITOL TEST measures permeability functionally rather than by proxy, and where the question genuinely matters it is the more defensible choice.

Ingredients with evidence in our library

• Probiotics and synbioticssolid -- 30 rows, 6 human -- including a systematic review and meta-analysis of clinical trials specifically assessing gut integrity reinforcement. The largest signal on this marker in our library. (30 studies in our library, 6 in people)
• Butyrate, and the fibres that produce itsolid -- 21 rows, 8 human. Butyrate is the primary energy source for colonocytes and directly upregulates tight junction proteins -- it is the most mechanistically direct barrier nutrient there is. Producing it from fermentable fibre is generally preferable to swallowing it. (21 studies in our library, 8 in people)
• Zinc (and zinc-carnosine)solid -- 11 rows, 7 human -- an unusually high human proportion, from intervention surveys for intestinal permeability. Zinc is required for tight junction assembly, and zinc-carnosine specifically has trial evidence in gastric and small-intestinal barrier protection including NSAID-induced damage. (11 studies in our library, 7 in people)
• L-glutaminemixed -- 9 rows -- a systematic review and meta-analysis of clinical trials on glutamine supplementation. Glutamine is the preferred fuel of small-intestinal enterocytes. Evidence is better in stressed states (burns, critical illness, athletes) than in general wellness use, and that distinction should travel with it. (9 studies in our library, 1 in people)
• Bovine colostrum / serum-derived immunoglobulinemerging -- 7 rows, 4 human -- serum-derived bovine immunoglobulin promoting barrier integrity and lowering inflammation. One of the more specific interventions with a direct barrier endpoint. (7 studies in our library, 4 in people)
• Curcuminemerging -- 4 rows, all human -- including reduced gut barrier damage during exertional heat stress, a real and measurable challenge model. (4 studies in our library, 4 in people)
• Polyphenols, beta-glucan and inulinemerging -- 13 rows combined -- beta-glucan and inulin intake associated with reduced Crohn's risk; green tea extract decreased circulating endotoxin and fasting glucose together. (13 studies in our library, 4 in people)
• ⚠️ Stopping NSAIDs where possible -- the biggest subtractionsolid -- NSAIDs increase small-intestinal permeability reliably and substantially. Removing that is often larger than anything added, and it costs nothing. (349 studies in our library, 145 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Bloating, fatigue after eating, brain fog, and food reactions that broaden over time -- the permeability picture.
• ⚠️ THIS IS THE MORE DEFENSIBLE PERMEABILITY TEST. It measures the function directly: two sugars are drunk, and the ratio recovered in urine shows how much passed BETWEEN cells (lactulose, large, should not) versus THROUGH them (mannitol, small, normally absorbed). Where serum zonulin's commercial assay is disputed, this measures the thing itself.

What people often feel when it runs low

• A low ratio indicates an intact barrier.

Patterns it travels in

• LACTULOSE:MANNITOL vs ZONULIN -- when the question genuinely matters, this is the better test. Several published analyses found the widely-used commercial zonulin ELISA is not detecting zonulin but a related protein; the sugar test has no such problem.
• ⚠️ IT MEASURES THE SMALL INTESTINE MAINLY. Extended collection windows or added sugars (sucralose, erythritol) are needed to assess the colon, and not every laboratory does this.
• HIGH RATIO + hs-CRP HIGH is the barrier-to-inflammation route -- endotoxin crossing into portal circulation.
• ⚠️ NSAIDs RAISE IT RELIABLY AND SUBSTANTIALLY, as do alcohol, intense endurance exercise in heat, and recent gut infection. Ask about all four before interpreting.
• HIGH RATIO + COELIAC SEROLOGY -- exclude coeliac disease, where increased permeability is part of the established mechanism.

Ingredients with evidence in our library

• Polyphenol-rich foods -- the MaPLE trialsolid -- The best human evidence our brain holds for a whole-food gut-barrier intervention: a polyphenol-rich diet in older adults with increased permeability reduced serum zonulin and calprotectin, increased the tight-junction protein ZO-1, and increased SCFA-producing bacteria. Berries, green tea, cocoa, pomegranate, colourful vegetables, olive oil, coffee. (81 studies in our library, 19 in people)
• Zinc-carnosinesolid -- One of the three interventions with human trials using permeability ratios as the outcome. Also has evidence for gastric mucosal protection including NSAID-induced damage -- which matters, since NSAIDs are a leading cause of the problem. (11 studies in our library, 7 in people)
• L-glutaminemixed -- A systematic review and meta-analysis of clinical trials; the preferred fuel of small-intestinal enterocytes. ⚠️ Evidence is better in stressed states -- burns, critical illness, endurance athletes -- than in general wellness use, and that distinction should travel with it. (9 studies in our library, 1 in people)
• Butyrate and the fibres that produce itsolid -- Butyrate directly upregulates tight-junction proteins and fuels colonocytes -- the most mechanistically direct barrier nutrient there is. (296 studies in our library, 60 in people)
• ⚠️ Stopping NSAIDs where possiblesolid -- The largest single subtraction, and free. Our brain names three interventions with human trials that specifically used lactulose:mannitol (or lactulose:rhamnose) ratios as their OUTCOME -- L-glutamine, zinc-carnosine and polyphenols. Those are the ones with a direct permeability endpoint rather than a borrowed one. (349 studies in our library, 145 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Diarrhoea, often with urgency; blood or mucus in stool.
• Abdominal pain, weight loss, night-time symptoms that wake someone from sleep.
• Fatigue and anaemia.
• ⚠️ NIGHT-TIME SYMPTOMS, WEIGHT LOSS AND BLOOD ARE RED FLAGS and belong to a doctor, not a wellness plan.

What people often feel when it runs low

• A low calprotectin is strongly reassuring against inflammatory bowel disease -- and that is its single most valuable use.

Patterns it travels in

• CALPROTECTIN IS THE TEST THAT SEPARATES INFLAMMATORY BOWEL DISEASE FROM IBS, and it does so well enough to spare a great many colonoscopies. A normal calprotectin in someone with IBS-type symptoms is genuinely useful information.
• CALPROTECTIN HIGH + BLOOD IN STOOL + WEIGHT LOSS needs specialist assessment, not a supplement protocol.
• ⚠️ NSAIDs RAISE CALPROTECTIN, as do infections and (mildly) proton pump inhibitors. Ask before escalating -- a repeat off NSAIDs resolves a large share of borderline results.
• CALPROTECTIN NORMAL + ZONULIN HIGH + SYMPTOMS = permeability and symptoms without frank inflammation. A different problem, and a more responsive one.
• CALPROTECTIN HIGH + CELIAC SEROLOGY -- always check coeliac in this picture.

Ingredients with evidence in our library

• ⚠️ This is a diagnostic gate, not a nutrition target. 19 rows, 10 tagged.mixed -- A raised calprotectin means find the cause. Where inflammatory bowel disease is confirmed, treatment is medical -- and our library's small nutrition signal here should not be presented as an alternative to it. (19 studies in our library, 7 in people)
• Anthocyanin-rich extract (bilberry)emerging -- 2 rows, both human -- efficacy and safety of anthocyanin-rich extract in patients with ulcerative colitis, as an adjunct. (2 studies in our library, 2 in people)
• A polyphenol-rich dietemerging -- Reduced serum and faecal calprotectin in older adults with increased permeability -- a dietary pattern rather than a supplement, which is the more honest framing. (2 studies in our library, 1 in people)
• Pomegranate extractemerging -- A 12-week juice intervention with a modulatory effect on the relevant transcriptional profile. (1 studies in our library, 1 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Diarrhoea, urgency, blood or mucus in stool, abdominal pain, weight loss -- the same picture as raised calprotectin, because both come from neutrophils in the gut wall.
• ⚠️ RED FLAGS -- night-time symptoms, weight loss, blood -- belong to a doctor rather than a wellness plan.

What people often feel when it runs low

• Reassuring against active intestinal inflammation, and the main value of the test.

Patterns it travels in

• LACTOFERRIN AND CALPROTECTIN MEASURE THE SAME THING BY DIFFERENT ROUTES -- both are neutrophil proteins. Calprotectin is the more widely used and better standardised of the two; ordering both rarely adds information over ordering one well.
• EITHER ONE SEPARATES INFLAMMATORY BOWEL DISEASE FROM IBS well enough to spare a great many colonoscopies. That is the single most valuable thing this class of test does.
• ⚠️ NSAIDs RAISE BOTH, as do infections and (mildly) proton pump inhibitors. A repeat off NSAIDs resolves a large share of borderline results.
• RAISED + COELIAC SEROLOGY -- always check coeliac in this picture.
• ⚠️ BREASTFED INFANTS have naturally high faecal lactoferrin from breast milk, which makes the test uninterpretable in that group.

Ingredients with evidence in our library

• ⚠️ A diagnostic gate, not a nutrition targetsolid -- A raised result means find the cause. Where inflammatory bowel disease is confirmed, treatment is medical, and our brain is explicit that no food lowers these markers the way fibre lowers LDL. (19 studies in our library, 7 in people)
• Polyphenol-rich diet -- a modest, real, honestly-sized effectemerging -- The MaPLE RCT produced a modest reduction in calprotectin -- much smaller than treating diagnosed inflammatory bowel disease, and our own matrix says so in those words. (2 studies in our library, 1 in people)
• Stopping NSAIDs where possiblesolid -- The commonest reversible cause of a mildly raised result, and worth excluding before any escalation. (349 studies in our library, 145 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Interpreted by some practitioners as an active mucosal immune response to a pathogen or to food antigens.
• ⚠️ BOTH DIRECTIONS ARE OVER-INTERPRETED. Our own `Panels/Gut-Microbiome.md` is blunt about this: sIgA's biology is well established in basic immunology, but there is NO validated clinical cutoff or outcome-based reference range the way there is for calprotectin (cite: Mucosal Immunology review, PMC3774538). Most of the literature is mechanistic and research-context, not validated diagnostic use.

What people often feel when it runs low

• Frequent gut infections and food-borne illness that hits harder than it does other people.
• Recurrent respiratory infections -- sIgA guards every mucosal surface, not only the gut.
• Symptoms overlapping food reactivity and gut inflammation.
• Associated with sustained stress and high cortisol, which suppress mucosal antibody production.

Patterns it travels in

• sIgA LOW + FREQUENT INFECTIONS + HIGH CORTISOL is the most coherent story this marker tells -- sustained stress suppresses mucosal immunity, and that is better documented than any nutrient effect.
• ⚠️ CHECK TOTAL IgA FIRST. Selective IgA deficiency affects roughly 1 in 500 people and is the commonest primary immunodeficiency. Someone with it will have a low sIgA for a genetic reason, and -- importantly -- their COELIAC SEROLOGY WILL BE FALSELY NEGATIVE, because the standard test is an IgA antibody. That single check prevents a real missed diagnosis.
• sIgA + CALPROTECTIN together separate immune activity from actual intestinal inflammation.
• sIgA LOW + ZINC LOW + VITAMIN A LOW + LOW PROTEIN INTAKE -- the deficiency picture where repletion is plausible. In an already well-nourished adult it is not.

Ingredients with evidence in our library

• Adequate protein, zinc and vitamin A -- in deficiency, and honestly framedemerging -- Our brain's food-to-marker matrix puts it precisely: these support normal mucosal antibody production in DEFICIENCY, and are not proven to raise sIgA further in a replete adult. Vitamin A's link is mechanistic and from animal and malnutrition research; dedicated human RCTs isolating its effect on sIgA in well-nourished adults are thin, and `Panels/Gut-Microbiome.md` tags it [TRADITIONAL/EMERGING] for exactly that reason. (22 studies in our library, 6 in people)
• Bovine colostrumemerging -- 6 rows, 3 human -- protective mechanisms of milk immunoglobulin against intestinal protozoal infection. The most specific mucosal-immunity intervention our library holds. (6 studies in our library, 3 in people)
• Beta-glucan (baker's yeast 1,3/1,6)emerging -- 2 rows, both human -- dietary beta-glucan supporting upper respiratory mucosal immune function. A mucosal endpoint measured directly rather than inferred. (2 studies in our library, 2 in people)
• Probiotics -- strain-specific, not a category claimemerging -- Some small trials suggest certain strains raise sIgA. `Panels/Gut-Microbiome.md` is explicit that this is strain- and product-specific rather than a general 'probiotics raise sIgA' claim -- and that distinction is the difference between a truthful page and a marketing one. (1 studies in our library, 0 in people)
• Reducing sustained stress loademerging -- Cortisol suppresses mucosal IgA production. Where a low sIgA has an identifiable cause in a well-fed person, this is more often it than a nutrient gap. (22 studies in our library, 6 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• This entry is about how to read a commercial stool panel, not about a symptom.
• ⚠️ A COMMERCIAL STOOL PANEL BUNDLES VALIDATED AND UNVALIDATED MEASURES IN ONE REPORT. Fecal calprotectin, fecal elastase and H. pylori antigen are validated tests with real reference ranges. The 'dysbiosis index', beta-glucuronidase interpretation, and the personalised supplement recommendations are not, and they arrive on the same page looking equally authoritative. Read the validated lines; treat the rest as hypothesis.

What people often feel when it runs low

• Same caveat.

Patterns it travels in

• READ THE VALIDATED LINES FIRST: fecal calprotectin (inflammatory bowel disease versus IBS), fecal elastase (exocrine pancreatic function), and H. pylori antigen. Each has published performance characteristics.
• ⚠️ PCR-BASED PATHOGEN DETECTION FINDS DNA, NOT NECESSARILY LIVE INFECTION -- and detects organisms at levels that carry no clinical meaning. A positive line does not automatically mean treat.
• ⚠️ 'COMMENSAL' AND 'OPPORTUNISTIC' BACTERIA REPORTED AGAINST A REFERENCE RANGE imply a validated normal that does not exist. There is no agreed healthy microbiome composition.
• WHERE THE PANEL EARNS ITS PLACE: a genuine diagnostic question in a symptomatic person, read selectively. Where it does not: screening a well person, or generating a supplement list.
• COMPARE ONLY LIKE WITH LIKE -- results from different platforms are not comparable, and a change between providers is not a change in the person.

Ingredients with evidence in our library

• ⚠️ The report's supplement recommendations are the least evidence-based part of itcontested -- They are generated by an interpretation layer, often by a company with products to sell, sitting on top of measurements that may themselves be sound. The sequencing being technically competent does not make the advice on page 12 evidence-based.
• What actually moves the gut, test or no testsolid -- Plant variety and fermentable fibre (SCFA production, 570 rows), fermented foods (Stanford RCT: diversity plus 19 inflammatory proteins), polyphenol-rich foods (MaPLE: zonulin, calprotectin, ZO-1), and strain-matched probiotics for a named indication. None of these requires the panel. (570 studies in our library, 169 in people)
• Act on the validated findingssolid -- A raised calprotectin means find the cause. A low elastase means assess pancreatic function and replace the fat-soluble vitamins. A positive H. pylori in a symptomatic person means eradication therapy. Those are real actions from a real test.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• This entry is about how to read a commercial stool panel, not about a symptom.
• ⚠️ A COMMERCIAL STOOL PANEL BUNDLES VALIDATED AND UNVALIDATED MEASURES IN ONE REPORT. Fecal calprotectin, fecal elastase and H. pylori antigen are validated tests with real reference ranges. The 'dysbiosis index', beta-glucuronidase interpretation, and the personalised supplement recommendations are not, and they arrive on the same page looking equally authoritative. Read the validated lines; treat the rest as hypothesis.

What people often feel when it runs low

• Same caveat.

Patterns it travels in

• READ THE VALIDATED LINES FIRST: fecal calprotectin (inflammatory bowel disease versus IBS), fecal elastase (exocrine pancreatic function), and H. pylori antigen. Each has published performance characteristics.
• ⚠️ PCR-BASED PATHOGEN DETECTION FINDS DNA, NOT NECESSARILY LIVE INFECTION -- and detects organisms at levels that carry no clinical meaning. A positive line does not automatically mean treat.
• ⚠️ 'COMMENSAL' AND 'OPPORTUNISTIC' BACTERIA REPORTED AGAINST A REFERENCE RANGE imply a validated normal that does not exist. There is no agreed healthy microbiome composition.
• WHERE THE PANEL EARNS ITS PLACE: a genuine diagnostic question in a symptomatic person, read selectively. Where it does not: screening a well person, or generating a supplement list.
• COMPARE ONLY LIKE WITH LIKE -- results from different platforms are not comparable, and a change between providers is not a change in the person.

Ingredients with evidence in our library

• ⚠️ The report's supplement recommendations are the least evidence-based part of itcontested -- They are generated by an interpretation layer, often by a company with products to sell, sitting on top of measurements that may themselves be sound. The sequencing being technically competent does not make the advice on page 12 evidence-based.
• What actually moves the gut, test or no testsolid -- Plant variety and fermentable fibre (SCFA production, 570 rows), fermented foods (Stanford RCT: diversity plus 19 inflammatory proteins), polyphenol-rich foods (MaPLE: zonulin, calprotectin, ZO-1), and strain-matched probiotics for a named indication. None of these requires the panel. (570 studies in our library, 169 in people)
• Act on the validated findingssolid -- A raised calprotectin means find the cause. A low elastase means assess pancreatic function and replace the fat-soluble vitamins. A positive H. pylori in a symptomatic person means eradication therapy. Those are real actions from a real test.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• This entry is about what a direct-to-consumer report can and cannot tell someone.
• ⚠️ 16S SEQUENCING AND SHOTGUN METAGENOMICS ARE DIFFERENT TESTS WITH DIFFERENT RESOLUTION. 16S reads one bacterial gene and typically resolves to genus; shotgun sequences everything present and can reach species and strain, and can see fungi and viruses that 16S cannot. Their outputs are not comparable, and neither are their diversity numbers.
• There are no agreed reference ranges for a 'healthy' microbiome, no standardisation between companies, and results from the same sample sent to different providers can differ substantially.

What people often feel when it runs low

• Same caveats.

Patterns it travels in

• ⚠️ THE PERSONALISED RECOMMENDATIONS ARE THE WEAKEST PART. Reports typically pair an unvalidated 'score' with food and supplement suggestions -- often for products the same company sells. The sequencing may be technically sound while the interpretation layer on top of it is not evidence-based.
• WHERE THESE TESTS GENUINELY HELP: as a research tool, and for tracking one person's change over time on the SAME platform. That is a real, modest use.
• SAMPLE HANDLING MATTERS -- time to stabilisation, temperature, and which part of the stool was sampled all shift the result.
• WHAT ANSWERS MORE FOR LESS: fecal calprotectin (validated, for inflammation), coeliac serology with total IgA, fecal elastase where symptoms are digestive, and a food-and-symptom diary. Each has a validated reference range that a microbiome report does not.

Ingredients with evidence in our library

• ⚠️ The intervention that works is the same regardless of what the report sayssolid -- Plant variety, fermented foods, and fermentable fibre raise diversity and SCFA production in everyone. No commercial report has been shown to identify a person for whom different advice works better -- which is the specific claim personalisation rests on. (570 studies in our library, 169 in people)
• Fermented foodssolid -- The Stanford RCT (36 adults, 10 weeks, Cell 2021) raised diversity and lowered 19 inflammatory proteins where an equally high-fibre arm did not. Applicable without any test at all. (81 studies in our library, 19 in people)
• Spend the money on a validated test instead, where there is a real questionsolid -- Calprotectin for suspected inflammation, coeliac serology with total IgA, fecal elastase for digestive symptoms. All validated, all cheaper, all actionable.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Generally favourable, and not a target to maximise for its own sake.

What people often feel when it runs low

• Bloating, irregular bowel habit, and food tolerance that narrows over time.
• Travels with a narrow diet, recent or repeated antibiotics, low fibre intake, and highly processed eating.
• ⚠️ LOW DIVERSITY IS NOT A DIAGNOSIS. Our own `Panels/Gut-Microbiome.md` tags it [CONTESTED as a universal marker]: a 2021 study testing whether alpha diversity distinguishes Parkinson's disease and multiple sclerosis patients from controls found it was NOT a reliable marker in those conditions (cite: Brain Communications 2021, PMC8195527). Diversity's meaning is disease-context-dependent -- 'more is always better' is not supported.

Patterns it travels in

• LOW DIVERSITY + LOW SCFAs + HIGH ZONULIN is the coherent dysbiosis picture, and all three respond to the same intervention: variety of plant fibre.
• LOW DIVERSITY + RECENT ANTIBIOTICS -- recovery takes months, and repeated courses compound it. Worth knowing before concluding anything about diet.
• DIVERSITY + hs-CRP -- the Stanford fermented-food RCT moved diversity and 19 inflammatory proteins including IL-6 together, which is the clearest human link between the two.
• ⚠️ 16S vs SHOTGUN SEQUENCING ARE NOT THE SAME TEST and their diversity numbers are not comparable. Never compare a result from one platform against a reference built on another.

Ingredients with evidence in our library

• Plant variety -- the '30 different plants a week' targetsolid -- Our brain names this as the most evidence-aligned lever for raising diversity, more so than any single supplement. Different fibres feed different producers, which is why variety beats quantity of any one fibre. (570 studies in our library, 169 in people)
• Fermented foodssolid -- The Stanford RCT (36 healthy adults, 10 weeks, Cell 2021) found a fermented-food diet increased overall microbial diversity and lowered 19 inflammatory proteins including IL-6 -- while an equally high-fibre diet did NOT move diversity in the same window. That contrast is the single most interesting finding in this whole section, and it argues for fermented foods specifically rather than fibre alone. (81 studies in our library, 19 in people)
• Fermentable fibre and prebioticssolid -- 108 rows across the prebiotic tags, 30 human. Consistently increases beneficial bacteria and SCFA production across RCTs. Introduce gradually in anyone with active IBS or SIBO symptoms. (108 studies in our library, 30 in people)
• Polyphenolssolid -- Largely unabsorbed in the small intestine and metabolised by colonic bacteria -- which is why polyphenol supplementation shows up in microbiota-composition studies at all. (81 studies in our library, 19 in people)
• ⚠️ Probiotics do not reliably raise diversitycontested -- They add transient passengers rather than changing the resident community, and most strains are undetectable weeks after stopping. Worth saying, because raising diversity is precisely what they are usually sold to do. (81 studies in our library, 19 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Very high fecal SCFAs may reflect malabsorption or rapid transit rather than a thriving microbiome.

What people often feel when it runs low

• Constipation or sluggish transit.
• Bloating that worsens on a low-fibre diet rather than improving.
• Poor barrier symptoms -- the fatigue-after-eating and brain-fog pattern.
• Low SCFA production travels with low microbial diversity, which travels with a narrow diet, antibiotics, and low fibre intake.
• ⚠️ FECAL SCFA MEASUREMENT IS AWKWARD TO INTERPRET: most SCFAs produced are ABSORBED by the colon, so what appears in stool is the leftover. A LOW fecal butyrate can mean poor production or excellent absorption, and the test cannot tell you which. This limitation is rarely stated by the companies selling it.

Patterns it travels in

• SCFAs ARE THE MECHANISM UNDER MOST OF THE GUT PANEL. Butyrate fuels colonocytes and maintains tight junctions; propionate acts on liver metabolism; acetate reaches systemic circulation and appetite signalling. When a fibre or probiotic study shows a benefit, this is usually the route.
• LOW SCFA + HIGH ZONULIN + LOW DIVERSITY is the coherent dysbiosis picture, and all three respond to the same intervention -- fermentable fibre variety.
• LOW SCFA + HS-CRP HIGH -- the butyrate-to-inflammation link, running through both barrier integrity and direct regulatory T-cell effects.
• SCFA + FASTING GLUCOSE / HBA1C -- our library holds SCFA production enhancing carbohydrate metabolism, and the incretin route is how gut fibre reaches blood glucose.
• ⚠️ FIBRE DIVERSITY BEATS FIBRE QUANTITY. Different fibres feed different producers; a single supplemented fibre at high dose does less than a varied intake, and is far more likely to cause bloating.
• ⚠️ INCREASE FIBRE SLOWLY. A rapid increase in fermentable fibre in someone with SIBO or IBS reliably makes symptoms worse before better, and that is the commonest reason people abandon the one intervention with the best evidence.

Ingredients with evidence in our library

• Butyrate and butyrate-producing fibressolid -- 296 rows, 60 human -- the largest gut signal in our entire library. Producing butyrate from fermentable fibre reaches the colon in a way that oral butyrate largely does not, which is why the food route is preferred where it is tolerated. (296 studies in our library, 60 in people)
• Prebiotics -- inulin, FOS, GOSsolid -- 108 rows across both prebiotic tags, 30 human. The most direct lever: these are the substrates SCFA production runs on. (108 studies in our library, 30 in people)
• Resistant starchsolid -- 30 rows, 8 human. Cooked-and-cooled potato, rice and legumes; green banana. Reaches the colon intact and is one of the most butyrogenic substrates known. (30 studies in our library, 8 in people)
• Probioticssolid -- 81 rows, 19 human -- including polyphenol supplementation shifting both microbiota composition and fecal SCFAs together. (81 studies in our library, 19 in people)
• Xylooligosaccharides (XOS)emerging -- 18 rows -- effective at unusually low doses compared with inulin, which matters for anyone who bloats on standard prebiotics. (18 studies in our library, 2 in people)
• Polyphenolssolid -- Largely non-absorbed in the small intestine and metabolised by colonic bacteria -- which is why polyphenol supplementation shows up in SCFA and microbiota composition studies rather than only in antioxidant ones. (81 studies in our library, 19 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• No direct symptoms -- this is a mechanism marker rather than a felt one.
• The claimed relevance is oestrogen recirculation: beta-glucuronidase produced by gut bacteria cleaves the glucuronide tag the liver attached to oestrogen for excretion, freeing it to be reabsorbed. That is the 'estrobolome' idea, and the enzymology is real.
• Where it matters, symptoms would be those of higher oestrogen exposure -- heavy periods, breast tenderness, worsening premenstrual symptoms.
• ⚠️ THE MECHANISM IS BETTER ESTABLISHED THAN THE CLINICAL EVIDENCE. Our library holds 22 rows and NONE of them are human trials showing that lowering this enzyme changes an outcome. Say mechanism, not benefit.

What people often feel when it runs low

• No recognised concern. The enzyme also has legitimate functions.

Patterns it travels in

• BETA-GLUCURONIDASE HIGH + OESTROGEN METABOLITES -- the estrobolome hypothesis. Plausible, mechanistically coherent, and short on outcome data.
• BETA-GLUCURONIDASE ALSO MATTERS FOR DRUG TOXICITY -- it deconjugates drug metabolites in the gut, which is a well-documented cause of chemotherapy-related gut injury. That is the strongest evidence this enzyme has, and it is not a wellness context.
• HIGH ENZYME + LOW FIBRE + LOW DIVERSITY -- fibre and the SCFA-producing community are associated with lower activity.
• ⚠️ THIS APPEARS ON COMMERCIAL STOOL PANELS AND IS OFTEN OVER-INTERPRETED. Treat a raised value as a prompt to look at fibre, diversity and bowel transit, not as a diagnosis of oestrogen dominance.

Ingredients with evidence in our library

• Adequate fibre and regular bowel transit -- the most evidence-aligned leveremerging -- Higher fibre intake is associated with lower faecal beta-glucuronidase activity, plausibly by diluting faecal bile and oestrogen concentration and speeding transit. Our own `Panels/Gut-Microbiome.md` tags this [EMERGING] and notes that dedicated large human RCTs isolating this enzyme as an outcome are limited -- which is the accurate weight to give it. (22 studies in our library, 12 in people)
• Calcium-D-glucarateemerging -- 7 rows -- inhibits the enzyme directly, which is a specific and real mechanism. ⚠️ None of our rows are human trials with a clinical outcome. The mechanism is established; the benefit is not, and the page must not blur those. (7 studies in our library, 0 in people)
• ⚠️ Cruciferous vegetables -- the popular claim, graded honestlycontested -- Commonly recommended for oestrogen-metabolism support. Our brain grades this [CONTESTED] in two separate files: the human RCT evidence that cruciferous compounds meaningfully change hormone OUTCOMES is thinner than the underlying biochemistry suggests. Eat them -- they are excellent food -- but not on the strength of this claim. (2 studies in our library, 0 in people)
• ⛔ What this marker cannot docontested -- The estrobolome mechanism is real and actively studied (cite: gut microbial beta-glucuronidase and oestrogen metabolism review, PMC10416750). But `Panels/Gut-Microbiome.md` states outright that using a single faecal measurement to diagnose or guide treatment of one person's hormonal symptoms is NOT backed by outcome trials -- it is meaningfully earlier-stage science than, say, coeliac serology. Never present it as a diagnosis of 'oestrogen dominance'. (22 studies in our library, 12 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Normal, meaning exocrine pancreatic function is adequate.

What people often feel when it runs low

• Pale, greasy, floating stools that are hard to flush -- steatorrhoea, and the most specific sign there is.
• Bloating, wind and cramping after fatty meals specifically.
• Unintended weight loss despite a normal or increased appetite.
• Deficiency of the fat-soluble vitamins A, D, E and K, and often B12 -- a scatter of deficiencies on a panel that look unrelated until this test explains all of them at once.
• ⚠️ FECAL ELASTASE IS THE RIGHT TEST WHEN THE SYMPTOMS ARE DIGESTIVE -- serum amylase and lipase are poor measures of digestive capacity. This measures whether the pancreas actually delivers enzymes into the gut.

Patterns it travels in

• DIAGNOSTIC ACCURACY, STATED HONESTLY [SOLID]: at a 200 mcg/g cutoff, a 2025 meta-analysis (13 studies, 888 patients) found pooled sensitivity 94% and specificity 69%; a 100 mcg/g cutoff raised specificity to 82% but dropped sensitivity to 88%. Against the gold-standard secretin stimulation test, sensitivity was 77% with specificity 88%. (cite: de la Iglesia D et al., United European Gastroenterology Journal 2025; PubMed 29374614)
• ⚠️ THAT SPECIFICITY MATTERS: performance is strongest as a SCREENING tool in high-risk groups -- cystic fibrosis, chronic pancreatitis -- and our own panel file counsels more caution using it stand-alone in low-risk asymptomatic people, where false positives are likelier.
• LOW ELASTASE + LOW VITAMIN A, D, E, K + LOW B12 is the malabsorption picture, and finding the cause explains every one of those deficiencies.
• LOW ELASTASE + DIABETES -- pancreatic exocrine insufficiency is far commoner in diabetes than generally appreciated, since the same organ is affected.
• ⚠️ A WATERY SAMPLE DILUTES THE RESULT and can produce a falsely low elastase. Test on a formed stool.
• LOW ELASTASE + SIBO SYMPTOMS -- the two coexist often, and treating one without the other leaves symptoms in place.

Ingredients with evidence in our library

• ⚠️ Confirmed insufficiency is treated with prescription enzyme replacement, not nutritionsolid -- Our own panel file: diet SUPPORTS but does not substitute for enzyme replacement in a true deficiency. Over-the-counter digestive enzymes are a different product at a different dose, and conflating the two is a claim we should not make. (14 studies in our library, 9 in people)
• Replacing the fat-soluble vitamins the malabsorption costsolid -- A, D, E and K, plus B12 -- and these need measuring rather than assuming. This is the genuinely useful nutrition contribution here, and it is corrective rather than therapeutic. (14 studies in our library, 9 in people)
• Removing alcoholsolid -- The commonest modifiable cause of chronic pancreatic damage. A subtraction that addresses the cause rather than the consequence.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Burning or gnawing upper abdominal pain, often worse when hungry and eased by food.
• Bloating, early fullness, nausea, burping.
• ⚠️ MANY PEOPLE HAVE NO SYMPTOMS AT ALL. H. pylori is one of the commonest chronic infections in the world.
• Iron deficiency that will not correct, and B12 deficiency -- H. pylori impairs acid production and both absorptions depend on it. This is a genuinely under-recognised cause of refractory iron deficiency.
• ⚠️ RED FLAGS needing prompt assessment rather than testing alone: difficulty swallowing, vomiting, weight loss, anaemia, or any bleeding.

What people often feel when it runs low

• Negative, with the test-choice caveat below.

Patterns it travels in

• TEST CHOICE MATTERS MORE HERE THAN ALMOST ANYWHERE [SOLID]: a Cochrane review and accuracy studies found the UREA BREATH TEST most accurate (~98% sensitivity, ~84% specificity, ~92% overall), STOOL ANTIGEN close behind (~96% / ~83%), and SEROLOGY notably less accurate (~50-67% overall) -- because antibodies stay positive long after an infection has been treated and cleared. (cite: Cochrane CD012080; PMC10748425)
• ⛔ DO NOT USE SEROLOGY TO CONFIRM ERADICATION. It cannot distinguish current from past infection, and a great many people are re-treated on the strength of it.
• ⚠️ PPIs, ANTIBIOTICS AND BISMUTH CAUSE FALSE NEGATIVES on breath and stool testing. Stop PPIs for two weeks and antibiotics for four before testing, or the result is not interpretable.
• H. PYLORI + REFRACTORY IRON DEFICIENCY -- testing and treating is a recognised route to resolving iron deficiency that has resisted everything else.
• H. PYLORI + B12 LOW / MMA HIGH -- the same acid-suppression mechanism.

Ingredients with evidence in our library

• ⚠️ No dietary intervention reliably eradicates confirmed H. pylorisolid -- Our panel file is unambiguous: eradication requires prescription antibiotic and PPI combination therapy. Anything else is adjunct at best, and presenting a supplement as an alternative would leave a treatable infection in place.
• Zinc-carnosine -- as an adjunct, which is exactly how our brain frames itemerging -- Has evidence alongside standard antibiotic triple therapy, not as a replacement for it. It also has independent evidence for gastric mucosal protection including NSAID-induced damage. (11 studies in our library, 7 in people)
• Correcting the iron and B12 afterwardssolid -- Eradication removes the cause; it does not refill the stores. Both need measuring and correcting alongside. (2486 studies in our library, 1350 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• Bloating that builds through the day and is worse after carbohydrate -- often described as looking pregnant by evening.
• Excessive wind, abdominal distension, cramping.
• Diarrhoea (more often with hydrogen-predominant results) or constipation (more often with methane-predominant, now called intestinal methanogen overgrowth).
• Fat malabsorption in more marked cases, with deficiencies of A, D, E, K -- and B12 deficiency, because the bacteria consume it.
• Symptoms that get WORSE on fibre and probiotics, which is the opposite of what most gut advice predicts and is a useful clue in itself.

What people often feel when it runs low

• A negative test does not exclude the symptoms having a real cause -- it redirects the search.

Patterns it travels in

• ⚠️ SIBO BREATH TESTING IS GENUINELY CONTESTED AND THE PAGE SHOULD SAY SO. Lactulose breath testing has poor specificity -- a rapid transit time produces the same early rise as bacterial overgrowth. Glucose breath testing is more specific but misses distal overgrowth. Consensus guidelines disagree with each other, and false positives are common.
• SIBO PICTURE + LOW B12 + HIGH FOLATE is a classic and useful combination -- gut bacteria CONSUME B12 and PRODUCE folate, so this pattern points at overgrowth from two directions at once.
• SIBO + LOW FERRITIN + LOW FAT-SOLUBLE VITAMINS is malabsorption, and it justifies taking the finding seriously.
• SIBO + PPI USE, or + previous abdominal surgery, or + hypothyroidism, or + diabetes with slow motility -- the cause is usually a MOTILITY problem, and treating the bacteria without addressing motility produces reliable relapse.
• METHANE-PREDOMINANT + CONSTIPATION is a distinct entity with a different treatment approach from hydrogen-predominant.
• SIBO SYMPTOMS + NORMAL TEST -- consider IBS, carbohydrate malabsorption, or pancreatic insufficiency. Fecal elastase is the cheap next question.

Ingredients with evidence in our library

• ⚠️ First, the test's own limits -- which our brain documents carefullycontested -- The North American Consensus exists because inconsistency across labs and protocols was undermining comparability (cite: Pimentel M et al., Am J Gastroenterol 2017, PMC5418558). Lactulose is poorly absorbed even in healthy people and reaches the colon fast regardless of small-bowel status, which drives a high false-positive rate; positivity has been reported as roughly similar between IBS patients and healthy controls, and lactulose showed poor agreement against glucose breath testing head-to-head (cite: PMC10496284). A positive lactulose test alone is not a confirmed diagnosis. (64 studies in our library, 43 in people)
• Addressing motility, not just the bacteriaemerging -- Overgrowth follows stasis. The durable levers are meal spacing, correcting hypothyroidism, reviewing motility-slowing medication, and treating the structural cause where there is one. Treating the bacteria without addressing motility produces reliable relapse, which is why so many people cycle through repeated courses. (2 studies in our library, 2 in people)
• ⚠️ Fibre and probiotics may make it worse initiallyemerging -- The one place on this whole panel where standard gut-health advice is the wrong advice. Someone with genuine overgrowth who follows general 'eat more fibre, take probiotics' guidance gets predictably worse and concludes they are broken. Introduce fermentable fibre gradually once the overgrowth is addressed, not before. (570 studies in our library, 169 in people)
• Correcting what the overgrowth costssolid -- Bacteria consume B12 and produce folate, so the low-B12-with-high-folate pattern is worth checking and correcting. Fat malabsorption costs vitamins A, D, E and K. These are real, measurable and fixable -- and more useful to act on than the breath result itself. (64 studies in our library, 43 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• The distinction this entry exists for: IBS and inflammatory bowel disease can feel similar from the outside, and calprotectin separates them.
• IBS: pain related to defaecation, change in stool frequency or form, bloating -- WITHOUT blood, weight loss, anaemia or night-time waking.
• ⚠️ IBD RED FLAGS: blood in stool, unintended weight loss, waking at night with symptoms, fever, anaemia, family history of IBD, onset over about age 50.

What people often feel when it runs low

• A NORMAL CALPROTECTIN IN SOMEONE WITH IBS-TYPE SYMPTOMS IS GENUINELY USEFUL INFORMATION -- it is strongly reassuring against IBD and spares an invasive investigation. It also validates the symptoms as real without implying inflammation.

Patterns it travels in

• CALPROTECTIN NORMAL + IBS SYMPTOMS = IBS is likely, and treatment can proceed without scoping in the absence of red flags.
• CALPROTECTIN RAISED + IBS SYMPTOMS = investigate. This is the test doing its job.
• ⚠️ A NORMAL CALPROTECTIN DOES NOT EXCLUDE COELIAC DISEASE -- different mechanism entirely. Check coeliac serology with total IgA separately.
• IBS + SIBO OVERLAP is substantial, and a fibre increase that helps one can worsen the other. Go slowly.
• IBS + BILE ACID DIARRHOEA is an under-diagnosed and very treatable cause of what gets labelled IBS-D.

Ingredients with evidence in our library

• A low-FODMAP diet, done properly -- with reintroductionsolid -- The best-evidenced dietary intervention for IBS symptoms. ⚠️ It is a diagnostic elimination with a structured reintroduction phase, NOT a permanent diet -- staying in the restriction phase long-term narrows the diet and reduces microbial diversity, which works against everything else on this panel. (570 studies in our library, 169 in people)
• Strain-matched probiotics, for IBS specificallyemerging -- A strain-specific systematic review and meta-analysis for IBS found outcome- and strain-specific efficacy rather than a general effect (cite: eClinicalMedicine 2021, PMC8529205). Match the studied strain to the studied outcome, or expect nothing. (81 studies in our library, 19 in people)
• ⚠️ Soluble fibre yes, insoluble often nomixed -- Psyllium has reasonable IBS evidence; wheat bran frequently worsens symptoms. And FOS specifically was found inconsistent, with some data suggesting it worsens IBS gas and bloating (cite: Wilson B et al., Am J Clin Nutr 2019). 'Eat more fibre' is not usable advice here. (108 studies in our library, 30 in people)
• Peppermint oil, enteric-coatedemerging -- One of the better-evidenced symptomatic treatments for IBS pain and bloating, acting as a smooth-muscle antispasmodic. (570 studies in our library, 169 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• A commercial panel typically returns a long list of 'reactive' foods -- often including the person's staples, which is the clue.
• ⚠️ FOOD-SPECIFIC IgG IS A NORMAL MARKER OF EXPOSURE AND TOLERANCE. Healthy people who eat a food regularly commonly test positive to it. That is the OPPOSITE of what a diagnostic test for a problem should show, and it is the core reason professional bodies advise against these panels.

What people often feel when it runs low

• A 'negative' result carries no diagnostic weight either, since the test is not measuring what it claims to.

Patterns it travels in

• ⛔ THIS IS THE PROFESSIONAL CONSENSUS POSITION, NOT A MINORITY VIEW. The AAAAI states there is no reliable scientific evidence that food-specific IgG indicates sensitivity or allergy. The EAACI task force concluded IgG4 testing against foods 'is not recommended as a diagnostic tool'. The CSACI issued a similar position statement. (cite: Stapel SO et al., EAACI Task Force Report, Allergy 2008, PMID 18489614; Carr S et al., CSACI position statement, Allergy Asthma Clin Immunol 2012, PMC3443017)
• ⚠️ THE HARMS ARE WELL DESCRIBED: because positives are common in healthy people eating a varied diet, panel-driven elimination risks unnecessary and sometimes extensive restriction, cost and anxiety -- and in children, genuine nutritional deficiency from cutting too many food groups on a test that is not measuring what it claims.
• IgG IS NOT IgE. Allergen-specific IgE, interpreted alongside clinical history, is the validated test where true allergy is suspected. Conflating the two is the commonest confusion in this area.
• WHAT TO DO INSTEAD -- our own panel file's list: a supervised elimination-and-reintroduction diet based on SYMPTOMS rather than a lab panel; formal allergy testing (skin prick or specific IgE) if true allergy is suspected; and hydrogen breath or genetic testing for specific intolerances such as lactose.

Ingredients with evidence in our library

• ⛔ The honest answer is not to buy the test.contested -- This entry exists so that someone who has already paid for a panel is told the truth about it, and so that we never sell one. Three national allergy bodies have published against it. Our own file title carries the word [CONTESTED] and our position matches theirs.
• A supervised elimination and reintroduction, driven by symptomssolid -- The evidence-based route to identifying a genuine food reaction -- structured, time-limited, and with reintroduction built in so the diet does not narrow permanently. This is the service worth offering where a panel is the thing worth declining.

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• In a gut panel the point is simple: COELIAC DISEASE MUST BE EXCLUDED BEFORE ANYTHING ELSE IS INVESTIGATED, because it explains permeability, inflammation, malabsorption and diversity loss all at once and has a definitive treatment.
• The commonest adult presentation is NOT diarrhoea -- it is iron deficiency that will not correct, fatigue, low bone density, mouth ulcers, headaches, low mood, infertility, and abnormal liver enzymes.

What people often feel when it runs low

• Negative, subject to the two caveats below.

Patterns it travels in

• ⛔ ALWAYS ORDER TOTAL IgA WITH tTG-IgA. Selective IgA deficiency affects roughly 1 in 500 and is MORE common in coeliac disease -- a negative screen in that person is not a true negative. Use IgG-based tests instead where IgA is deficient.
• ⛔ DO NOT REMOVE GLUTEN BEFORE TESTING IS COMPLETE. It normalises the antibodies and causes a false negative, sometimes delaying diagnosis by years. This is the commonest well-intentioned error in the whole gut panel.
• COELIAC + ZONULIN -- gluten is a direct and documented zonulin trigger in coeliac disease, which is where the entire zonulin literature began.
• COELIAC + FERRITIN LOW + B12 LOW + VITAMIN D LOW + LOW BONE DENSITY is the malabsorption cluster that usually leads to the diagnosis.
• COELIAC + THYROID ANTIBODIES + TYPE 1 DIABETES -- autoimmunity clusters; finding one warrants checking the others.

Ingredients with evidence in our library

• Strict gluten elimination -- the guideline-level standard of caresolid -- Our brain: one of the few places in integrative nutrition where the dietary intervention IS the standard of care, not an adjunct. Antibodies fall over months and the intestinal lining heals. (78 studies in our library, 40 in people)
• Correcting the deficiencies the malabsorption causedsolid -- Iron, B12, folate, vitamin D, calcium and zinc all need measuring and correcting. The diet stops the damage; it does not refill the stores. (1102 studies in our library, 601 in people)
• ⚠️ Non-coeliac gluten sensitivity is a different questioncontested -- Real for some people and poorly defined; a substantial share of what improves on gluten withdrawal turns out to be FODMAPs in wheat rather than gluten itself. Worth testing properly before committing to a lifelong restriction. (570 studies in our library, 169 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs high

• ⚠️ Increased too fast, fermentable fibre reliably causes bloating, wind and discomfort BEFORE it helps -- which is the commonest reason people abandon the intervention with the best evidence. Increase gradually.

What people often feel when it runs low

• Constipation, sluggish or irregular transit.
• Low microbial diversity and low SCFA production, with the barrier and inflammatory consequences that follow.
• Most people eat well under the recommended fibre intake, and the shortfall is one of the most consequential dietary gaps there is.

Patterns it travels in

• PREBIOTIC SUPPLEMENTATION CONSISTENTLY INCREASES beneficial bacterial abundance and SCFA production across RCTs, with improvements in stool frequency and consistency and some barrier markers [SOLID]. (cite: Holscher HD, Gut Microbes 2017)
• ⚠️ BUT IT IS NOT A UNIVERSALLY SAFE BLANKET RECOMMENDATION. Inulin and GOS show some benefit for IBS, while a systematic review and meta-analysis found the evidence for FOS specifically was inconsistent -- and some data suggested FOS could WORSEN IBS symptoms in a subset. (cite: Wilson B, Rossi M, Dimidi E, Whelan K, Am J Clin Nutr 2019)
• RESISTANT STARCH [EMERGING] -- plausible SCFA and barrier benefits, with an evidence base still limited by small samples, short durations and no dosage or type standardisation. (cite: MDPI Nutrients 2021)
• FIBRE VARIETY BEATS FIBRE QUANTITY -- different fibres feed different producers. A single supplemented fibre at high dose does less than a varied intake and causes more bloating.
• ⚠️ IN ACTIVE SIBO OR IBS, go slowly or address the overgrowth first.

Ingredients with evidence in our library

• A varied, plant-diverse diet -- the food-first answersolid -- Legumes, oats, garlic and onion, green banana, and cooled-then-reheated potatoes and rice for resistant starch. This is our own panel file's recommendation, and it outperforms any single supplemented fibre. (570 studies in our library, 169 in people)
• Inulin and GOSsolid -- 108 rows across the prebiotic tags, 30 human. The two with the most consistent trial support, including some benefit in IBS. (108 studies in our library, 30 in people)
• ⚠️ FOS -- the one to be careful withcontested -- Evidence inconsistent, and some data suggest it can worsen gas and bloating in a subset of IBS patients. Named specifically rather than folded into 'prebiotics', because the distinction is what makes the advice usable. (18 studies in our library, 2 in people)
• Resistant starchemerging -- 30 rows, 8 human. One of the most butyrogenic substrates known, and cheap -- cooling cooked potato or rice creates it at no cost. (30 studies in our library, 8 in people)
• Cereal and legume fibre, for the colorectal-risk questionsolid -- Our brain's best-graded diet-cancer relationship: RR 0.90 per 10 g/day of total fibre, with LEGUME fibre strongest at RR 0.62 and cereal fibre at 0.90; WCRF rates it 'strong evidence' -- a rare designation. Food-based, not purified fibre pills. (cite: PMC3213242) (570 studies in our library, 169 in people)

Counts are of studies held in our own citation library that name this marker and carry that ingredient tag. They describe how much evidence exists, not how well anything works, and none of this is medical advice or a claim to treat any condition.

What people often feel when it runs low

• This entry is about an intervention rather than a measurement -- glutamine is rarely measured clinically.
• The rationale: glutamine is the preferred fuel of small-intestinal enterocytes, and becomes conditionally essential when demand outstrips supply -- in burns, critical illness, major surgery, and heavy endurance training.

Patterns it travels in

• GLUTAMINE IS ONE OF THE THREE INTERVENTIONS with human trials using lactulose:mannitol ratios as the outcome -- so unlike most gut supplements, it has been tested against the thing it claims to fix.
• ⚠️ THE EVIDENCE IS BETTER IN STRESSED STATES THAN IN GENERAL WELLNESS USE. Burns, critical illness and athletes under heat stress are where it performs; a well person with mild bloating is a different population, and the trials do not transfer cleanly.
• GLUTAMINE + BUTYRATE serve different cells -- glutamine fuels the SMALL intestine's enterocytes, butyrate fuels the COLON's colonocytes. They are not interchangeable, which is rarely made clear.
• ⚠️ CAUTION IN LIVER DISEASE: glutamine is metabolised to ammonia, and in cirrhosis with encephalopathy risk that matters.

Ingredients with evidence in our library