Nutrients

Compounds in raw cruciferous vegetables and soy that compete with iodine uptake at the thyroid. Cooking deactivates most of them.

Preformed in aged, fermented and poorly chilled food. Triggers symptoms in people whose clearance is low.

Sugar-binding proteins in raw legumes and grains. Thorough cooking destroys them.

Accumulates up the marine food chain. The reason large predatory fish are limited in pregnancy.

Bind calcium into an insoluble salt. Relevant for calcium uptake and for anyone who forms calcium-oxalate stones.

The storage form of phosphorus in seeds, grains and legumes. Grips divalent minerals in the gut so they cannot be absorbed.

Broken down to uric acid. Matters for gout and hyperuricaemia, not for the general population.

Bitter surface compounds on quinoa and legumes. Rinsing removes most, and the clinical impact is low.

Polyphenols in tea, coffee and cocoa that chelate non-heme iron and can halve its absorption.

Builds up in aged and fermented food. Normally cleared by MAO-A, which is why it is dangerous on an MAO inhibitor.

The apolipoprotein lipoprotein lipase has to see before it will cleave a triglyceride.

The cell's energy currency. Used as the Mg-ATP complex, which is why magnesium status limits it.

Accessory electron carrier that raises the lyase activity of CYP17A1, shifting output toward androgens.

Flavin cofactor built from riboflavin. MTHFR and the monoamine oxidases both need it bound.

The iron-carrying porphyrin at the catalytic centre of the P450 enzymes, catalase and haemoglobin.

Oxidising co-substrate for thyroid peroxidase, and the reactive species glutathione peroxidase clears.

Co-substrate for every oxygenase, including the whole P450 family.

The oxidised electron carrier of catabolism. Built from niacin.

The reducing power behind every cytochrome P450 reaction, steroid synthesis step and glutathione recycle.

The universal methyl donor. COMT uses it to switch off catecholamines and oestrogens.

The selenium-containing amino acid built into the active site of the deiodinases and glutathione peroxidase. Not a bound cofactor but part of the protein itself.

The sugar donor in glucuronidation, which is how the body tags steroids and drugs for excretion.

The folate intermediate MTHFR reduces. It is also the form used to build thymidine for DNA.

Plant pigment the body converts to retinol as needed. Conversion is inefficient and varies a lot between people, and it needs fat in the meal to be absorbed at all.

Docosahexaenoic acid. Structural fat of the retina and brain, and the form that matters most in pregnancy.

Eicosapentaenoic acid. The omega-3 most of the inflammation and triglyceride evidence is built on.

Iron bound inside haem, from meat, poultry and fish. Absorbed by its own transporter, so phytate and tannins barely touch it.

The long-chain menaquinone used in most supplements. Half-life measured in days rather than hours, so one daily dose holds a steady level.

The circulating, active folate. MTHFR is the enzyme that makes it, so a slow MTHFR variant shows up as low 5-MTHF and high homocysteine.

Iron from plants and fortified foods. Absorbed through DMT1 in the ferrous state, so it is the form vitamin C rescues and the form phytate, tannins and calcium block.

The B12-shaped molecule in most algae and some fermented foods. It registers on some assays and does nothing in humans, so it is tracked separately rather than counted as B12.

The active coenzyme form of B6. This is what the enzyme actually binds, which is why supplements are often sold as P5P rather than pyridoxine.

Preformed vitamin A from animal foods. Ready to use, and the form that accumulates to toxicity if overdosed.

The menaquinone family, from fermented food and animal tissue. Longer-lived in blood than K1 and more active on bone and artery proteins.

Forms the micelles that carry the fat-soluble vitamins across the gut wall. Without fat in the meal, A, D, E, K and the carotenoids largely pass through.

Feeds the gut microbiome and slows glucose absorption. At high loads in a single meal it also lowers mineral uptake.

Supplies the amino acids every enzyme and hormone is built from. Also raises the absorption of several minerals eaten with it.

Pregnenolone after CYP17A1 hydroxylates it. One step from DHEA.

Steroid intermediate measured clinically to screen for 21-hydroxylase deficiency.

A metabolite of DHT with no androgen receptor activity of its own. It acts on the GABA-A receptor instead, which is how an androgen ends up changing anxiety and sleep without touching the androgen receptor at all.

Where carbohydrate, fat and protein breakdown all converge before entering the Krebs cycle.

Spent ATP, waiting for a phosphate back.

Carries nitrogen from muscle to liver, where it is handed to alpha-ketoglutarate by ALT.

Krebs cycle intermediate and the nitrogen acceptor in every transamination.

Accumulates when energy is scarce. Rising AMP is what activates AMPK.

Sits one step below testosterone and one step below oestrone. Aromatase can take it either way.

Amino acid AST moves nitrogen onto. Also feeds the urea cycle.

The inactive partner of cortisol. HSD11B1 switches it on in tissue, HSD11B2 switches cortisol off.

Buffers ATP in muscle and brain by holding a spare phosphate group.

The unsulfated adrenal androgen. Circulates mostly as its sulfate, DHEA-S, which is what labs measure.

What is left after a second iodine comes off T3 or reverse T3. Largely a clearance product.

Neurotransmitter for motivation and movement, and the direct precursor of noradrenaline.

Adrenaline. The end of the catecholamine chain and the fastest arm of the stress response.

The weaker oestrogen, and the dominant one after menopause because adipose aromatase keeps making it.

The hub of amino-acid nitrogen handling and the main excitatory neurotransmitter.

The smallest amino acid, a third of collagen by residue count, and a substrate for glutathione.

The committed precursor in cholesterol synthesis. HMGCR reduces it to mevalonate, and statins block that step.

Rises when the methylation cycle stalls. A useful readout of folate, B12 and B6 status, and an independent cardiovascular risk marker.

The absorbed, reduced form of iodine. TPO oxidises it before attaching it to thyroglobulin.

The product of the rate-limiting step of cholesterol synthesis.

Noradrenaline. Made from dopamine, and converted onward to adrenaline in the adrenal medulla.

Condenses with acetyl-CoA to start each turn of the Krebs cycle.

The charged form of creatine. Hands its phosphate to ADP to regenerate ATP in the first seconds of hard effort.

The first steroid made from cholesterol. Everything downstream, cortisol, androgens and oestrogens, starts here.

Amino acid that gives collagen its kinked structure. Hydroxylating it needs vitamin C.

The end of glycolysis. Goes to acetyl-CoA when oxygen is available and to lactate when it is not.

Monoamine made from tryptophan. Mostly gut-resident, and the precursor of melatonin.

The large protein whose tyrosine residues thyroid hormone is assembled on and stored in.

Influences how the body handles calcium, magnesium and vitamin D, and how much sex hormone stays free.

Bone mineral and signalling ion. A large calcium load in the same meal competes with non-heme iron for DMT1.

Builds cell membranes and acetylcholine, and feeds the methylation cycle through betaine.

Cofactor for iron export, connective-tissue crosslinking and the electron transport chain. High-dose zinc lowers it.

Carries single-carbon units for DNA synthesis and for recycling homocysteine back to methionine.

The raw material of thyroid hormone. T4 carries four iodine atoms and T3 carries three, so intake sets the ceiling on thyroid output.

Carries oxygen in haemoglobin and sits in the active site of several enzymes. Absorption is the bottleneck, not intake, which is why so much of the absorption layer points here.

Required by every ATP-dependent reaction, since the usable substrate is the Mg-ATP complex rather than ATP alone.

Cofactor for mitochondrial superoxide dismutase and several carbohydrate-handling enzymes.

The precursor of NAD+ and NADPH, which carry electrons for most of energy metabolism and every P450 reaction.

The long-chain marine fats EPA and DHA plus their plant precursor ALA. They sit in cell membranes and are the substrate for the resolvins that switch inflammation off.

The backbone of coenzyme A, so it sits upstream of fat oxidation and steroid hormone synthesis.

Bone mineral, and the phosphate group in ATP, DNA and every phosphorylation signal.

Main intracellular cation. Drives membrane potential and blood pressure regulation.

The precursor of FAD. Low riboflavin lowers FAD, and MTHFR needs FAD to work.

Built directly into selenoenzymes as selenocysteine. Without it the deiodinases cannot convert T4 to T3.

Main extracellular cation, and the ion most nutrient transporters in the gut are coupled to.

Cofactor for pyruvate dehydrogenase. Without it pyruvate cannot enter the Krebs cycle.

Needed for vision, immune function and steroidogenesis. Measured two ways in the food data, as retinol activity equivalents and as international units.

Needed by methionine synthase and by one mitochondrial enzyme. Absorption needs intrinsic factor, so it fails on stomach problems long before intake does.

Cofactor for over a hundred enzymes, most of them handling amino acids and neurotransmitters.

Cofactor for collagen synthesis and catecholamine production, and the single strongest lever on non-heme iron absorption.

Acts as a hormone rather than a classical vitamin. Governs calcium absorption and a wide set of immune genes.

Chain-breaking antioxidant inside cell membranes. Regenerated by vitamin C after it does its job.

Activates the proteins that clot blood and the ones that steer calcium into bone.

Structural and catalytic cofactor in hundreds of enzymes, including steroidogenic ones. Shares absorption machinery with iron and copper.

The soluble fiber in oats and barley. Binds bile acids in the gut, which is the mechanism behind its effect on LDL.

A group of linoleic acid isomers found in ruminant fat and dairy.

The active polyphenol in turmeric. Poorly absorbed on its own.

Converted by oral bacteria to nitrite and then to nitric oxide, which widens blood vessels.

The two carotenoids concentrated in the macula, where they filter blue light.

The pungent alkaloid in black pepper. Slows the enzymes that clear curcumin, so more of it reaches the blood.

Live bacteria in fermented food, counted as colony-forming units. Effects are strain-specific, so the count alone says little.

Formed when raw cruciferous vegetables are chopped or chewed. Activates the NRF2 antioxidant response.