The B vitamins are water-soluble vitamins that work in energy metabolism. Each has its own page:

Choline

[edit]

Choline is a nutrient used to make phosphatidylcholine and acetylcholine. Egg yolks and liver are the richest food sources.

History

[edit]

Charles Best, one of the discoverers of insulin, later showed that choline, a component of lecithin, can prevent fatty degeneration of the liver.[1]

Dosing

[edit]

In Nutrition for Women, the cited source gives about 500 mg each for inositol and choline as part of a daily supplement regimen alongside protein, minerals, and other vitamins.[2] It recommends taking inositol and probably choline alongside supplemental biotin, since large doses of biotin alone were toxic in animal experiments; liver is a good dietary source of both.[2]

Function/Mechanism of Action

[edit]

Choline is known to stimulate acetylcholine synthesis, which may help promote normal parasympathetic innervation.[2] On a cellular level, acetylcholine shifts the proportion of fuels mitochondria use, increasing the oxidation of alpha-ketoglutarate (with carbon dioxide production) and increasing the efficiency of energy conservation (phosphorylation), so that less oxygen is needed, in contrast to adrenaline's effect of increasing oxygen consumption.[3]

Peat's view

[edit]

Phosphatidylcholine containing two myristic acid groups can support cytochrome c oxidase activity, the mitochondrial respiratory enzyme that declines with aging.[4] The cited source also reports a choline supplement will stimulate lecithin synthesis in the body when adequate essential fatty acids are present, though it generally favored getting fresh lecithin from whole foods like eggs over relying on isolated oils, which oxidize and turn rancid when exposed to air.[2]

Folate

[edit]
Folic acid molecular structure
Folic acid molecular structure

Folic acid is the synthetic folate used in fortified foods and many supplements. Folate is the broader vitamin B9 family.

Folate dosing overview

[edit]

Ray Peat generally described 1 to 5 milligrams of folic acid a day as a safe range, sometimes citing 5 milligrams specifically alongside other B vitamins.[5][6][7]

Peat's view (folate)

[edit]

Pregnancy care uses folate for neural tube prevention under medical guidance. Food folates appear in liver and greens. High synthetic doses are a clinical topic, not a casual stack.

Suicide risk research

[edit]

A pharmacoepidemiologic study of 866,586 privately insured US adults found that months covered by an active folic acid prescription carried a 44% lower rate of suicide attempts and intentional self-harm than uncovered months. The dose involved was prescription-strength folic acid (typically 1 mg/day), not the smaller amounts in fortified flour or a multivitamin.[8] This is a claims-database association, not a controlled trial of folic acid itself, and does not resolve the food-folate-versus-synthetic-folic-acid question above.

Depression trials

[edit]

Add-on folate trials in depression are small, and the benefit varies by subgroup. In a 10-week randomized trial of 127 patients with major depression on fluoxetine, adding 500 µg folic acid improved Hamilton scores more than placebo overall, but the gain was confined to women (final score 6.8 vs 11.7; good response 93.9% vs 61.1%). Men showed a smaller rise in plasma folate and no significant fall in homocysteine.[9] In a 6-month double-blind trial among 41 psychiatric patients with borderline or definite folate deficiency (red-cell folate below 200 µg/L), methylfolate added to standard treatment improved clinical and social recovery in both the depressed and the schizophrenia groups.[10] Among 55 fluoxetine-resistant outpatients, low serum folate predicted poorer response to the next treatment step (7.1% vs 44.7% response), while low B12 and high homocysteine did not.[11] A 2016 review lists folate and B12 among nutrients that lower homocysteine and support mitochondria, and cites the first two trials above in its evidence table.[12] See Vitamin B12.

Cerebral folate note

[edit]

When folate receptor alpha autoantibodies block choroid-plexus transport, blood folate can remain normal while cerebrospinal-fluid 5-MTHF is low; high-dose folinic acid (leucovorin) is the form studied for that cerebral gap in autism because it can use the reduced folate carrier instead.[13][14] Details and prevalence figures are on Vitamin B9 and Autism.

Folate (vitamin B9) is required for cell division and DNA synthesis, which makes it especially important wherever cells are proliferating rapidly. Peat's clinical use of it centered on exactly this: short, targeted courses at times of high cell turnover or estrogen excess, rather than continuous daily supplementation.[15]

Dosing (folate)

[edit]

For supporting immune cell turnover, about 5 mg of folic acid daily for one to two weeks is effective.[16] For abnormal cervical cell changes, recommended 1–10 mg daily for a few weeks, alongside liver two or three times a week.[17] In both cases the dosing was a short, targeted course rather than continuous daily supplementation.

Structure/Chemical properties

[edit]

Folate is a B vitamin built from a pteridine ring, para-aminobenzoic acid, and one or more glutamate residues. "Folic acid" refers specifically to the fully oxidized synthetic form used in supplements and fortified food, distinct from the mixture of reduced folates found naturally in food.

Function/Mechanism of Action (folate)

[edit]

Folate acts as a coenzyme in one-carbon transfer reactions needed for synthesizing DNA precursors and for methylation reactions throughout the body. In rapid cell division, and in states of estrogen excess (which itself drives proliferation in estrogen-sensitive tissue), folic acid and other B vitamins are used up quickly, creating a relative deficiency even on an otherwise adequate diet.[18]

Medical uses/Effects

[edit]

Ehlers-Danlos hypermobility

[edit]

Hypermobile Ehlers-Danlos patients showed low methylfolate with elevated unmetabolized folate, linking MTHFR-related folate-processing failure to a treatable connective-tissue syndrome.[19]

Schizophrenia and folate status

[edit]

Blood folate runs lower in schizophrenia than in healthy controls, a pattern confirmed across dozens of pooled studies.[20] MTHFR C677T TT genotypes are overrepresented in schizophrenia cohorts and in pooled psychiatric meta-analyses; that is a folate-processing efficiency signal, not proof that methylfolate supplements treat psychosis.[21][22] In a small open-label case series of treatment-resistant schizophrenia, most patients carried antibodies that block the brain's folate receptor despite normal blood folate, and all but one of those given high-dose folinic acid on top of their existing medication improved; there was no placebo group, and no other cohort has tested it since.[23][24] See Schizophrenia, Methylation.

Aging

[edit]

Restricting dietary folate late in life reduced one-carbon anabolic biosynthesis in mice yet maintained frailty indices, body composition, and metabolic plasticity, suggesting age-dependent tradeoffs in folate requirements.[25] Peat considered folic acid important enough for cell proliferation and differentiation, particularly for supporting normal turnover of immune cells like phagocytes, that short supplemental courses are appropriate rather than treating it as something to avoid.[26] For abnormal cervical cell changes linked to rapid cell division and estrogen excess, he paired folic acid supplementation with liver (for other B vitamins), vitamin E, and topical progesterone.[27]

On methylated folate supplements specifically, Peat was cautious: he considered it risky to supplement methyl donors like methylfolate, choline, betaine, methionine, and SAMe in substantial quantity, and thought bad reactions some people report to methylfolate or methyl-B12 products are more likely allergic reactions, possibly related to manufacturing differences between products, than a specific problem with the methyl group itself.[28]

Autism and cerebral folate

[edit]

Cerebral folate deficiency is low 5-methyltetrahydrofolate in the brain or cerebrospinal fluid despite often-normal blood folate. One major cause is folate receptor alpha autoantibodies that block the primary choroid-plexus transporter.[29] Pooled FRAA prevalence in autism spectrum disorder was about 71% (series range 58%-76%), and ASD children were about 19-fold more likely to be FRAA-positive than typically developing controls without an ASD sibling.[29][30]

d,l-Leucovorin (folinic acid) can enter the brain via the reduced folate carrier when FRα is blocked; high-dose regimens used in autism trials are about 2 mg/kg per day (maximum 50 mg/day in the 2018 RCT).[30][31] Meta-analyzed leucovorin series in ASD with cerebral folate deficiency reported overall ASD symptom improvement in about 67% of treated individuals.[29] Binding FRAA titer also tracked leucovorin response in a 110-patient ASD clinic cohort.[32] Ordinary folic acid and methylfolate still depend heavily on FRα at the blood-brain barrier, so they do not reliably correct cerebral folate deficiency when that receptor is autoantibody-blocked. See Autism.

Side/Adverse effects

[edit]

Standard folic acid is generally well tolerated at nutritional doses; folic acid, like methylfolate, can be allergenic in some people independent of dose.[33] High-dose methyl-donor supplementation more broadly, he considered risky rather than routinely beneficial.[34]

Methylation

[edit]

Methylation is transfer of methyl groups in biochemistry, including DNA and detox pathways. B12 and folate participate. Marketing oversells methylation panels and direct-to-consumer MTHFR testing.

Peat's view (methylation)

[edit]

Epigenetic effects and imprinting mainly involve methylation and acetylation of chromosomes (DNA and histones), and carbon dioxide concentration during gestation may regulate how much of that imprinting persists in the fetus.[35] Methylation of histones is also a process that increases with aging.

Many people have been disturbed to learn that they have a "mutation" in a gene called MTHFR. This is an extremely common variation in a gene that relates to the activity of an enzyme that regulates methylation, i.e., the attachment of single carbon atoms to a great variety of molecules in the body.

— Ray Peat[36]

People with the less active MTHFR form have a slightly higher requirement for folate from ordinary foods (fruits, vegetables, milk, cheese, eggs, liver), with vitamins B2, B6, and B12 also involved in folate and methylation regulation.[37] The American College of Medical Genetics recommended against routine MTHFR polymorphism testing for thrombophilia, citing minimal clinical utility after meta-analyses failed to support coronary and venous-thromboembolism links.[38][37] Excess methylation of DNA has been associated with stress, cancer, and aging; choline as a methyl donor has been linked to prostate cancer risk in the same newsletter context.[37]

Autism

[edit]

In a 2025 Lebanese case-control study of 86 children with autism spectrum disorder and 86 matched controls, high homocysteine was five times more common in the autism group (29.1% vs. 5.8% of controls, and low folate (vitamin B9) was four times more common (41.9% vs. 10.5%,; vitamin B12 status did not differ significantly between groups.[39]

Schizophrenia and mood

[edit]

Lower blood folate in schizophrenia (meta-analysis, 1463 cases) and overrepresentation of MTHFR T677T in one cohort sit with shared 677TT vulnerability across schizophrenia, bipolar disorder, and unipolar depression.[40][41][42][43] See Schizophrenia, Depression.

Riboflavin

[edit]

Riboflavin (vitamin B2) is a coenzyme central to mitochondrial respiration. Peat's clearest writing on it is a case-history article connecting riboflavin deficiency to a family of conditions involving abnormal blood vessel overgrowth: rosacea, rhinophyma (the enlarged, bulbous nose sometimes seen in advanced rosacea), and pterygium (an overgrowth of tissue onto the cornea).[44]

Dosing (riboflavin)

[edit]

In the case histories, doses as small as 10 mg produced rapid, sometimes near-instantaneous effects on symptoms, taken for a period of a few weeks.[45]

Prior deficiency can raise the dose needed to correct it: in rats made riboflavin-deficient until corneal changes appeared, returning them to a standard, non-deficient diet no longer met the eye tissue's needs, and only a dose several times the normal requirement prevented the deficiency signs from recurring, so repletion after deficiency often requires more than baseline amounts.[46]

Structure/Chemical properties (riboflavin)

[edit]

Riboflavin is a flavin, built around an isoalloxazine ring with a ribitol side chain. In the body it is converted to the coenzymes FMN and FAD, central carriers in the mitochondrial electron transport chain.

Function/Mechanism of Action (riboflavin)

[edit]

Across several case histories, riboflavin deficiency blocks mitochondrial respiration and wastes glucose, and the tissue responds to this relative hypoxia by growing extra blood vessels to try to deliver more oxygen. In the cornea specifically, riboflavin is normally present in high concentration but the tissue is very susceptible to deficiency, since the cornea gets its oxygen partly straight from the air; anything that blocks this air contact, such as a contact lens, combined with riboflavin deficiency, can trigger the abnormal vessel ingrowth of pterygium.[47] The same underlying process produces rosacea when it occurs on the nose or cheeks instead of the eye, and oxygen deficiency separately causes connective tissue cells to overproduce collagen, which can further impede oxygen delivery and set up a self-reinforcing cycle once lumpy fibrous overgrowth has begun.[48] In six hypothyroid adults eating normal diets, a riboflavin-dependent red cell enzyme fell to the levels seen in riboflavin deficiency and returned to normal after two weeks of thyroxine with no vitamins given, which the authors took as evidence that thyroid hormone controls the conversion of riboflavin to its coenzyme forms in humans.[49]

Psoriasis

[edit]

Higher dietary riboflavin intake associates with lower psoriasis prevalence in adults; low riboflavin triggers inflammatory stress responses in keratinocytes that resolve when riboflavin is restored.[50]

Inborn errors of metabolism

[edit]

Systematic micronutrient screening identifies riboflavin (FAD) and niacinamide (NAD+) as cofactors that bypass many "incurable" monogenic mitochondrial diseases in cell and mouse models.[51]

Cellular senescence and Complex II

[edit]

Under DNA-damage stress, cells upregulate the riboflavin transporter SLC52A1, convert imported riboflavin to FAD, and transiently increase mitochondrial respiratory-chain complex II activity; maintaining elevated FAD and mitochondrial activity suppresses AMPK and p53 and delays stress-induced senescence.[52]

Medical uses/Effects (riboflavin)

[edit]

High-dose oral riboflavin (15 mg/kg) in a juvenile motor-neuron disease case progressively restored independent ventilation and daily function over months despite initial ventilator dependence.[53] Parkinson disease gut microbiome analysis links dysbiosis to decreased riboflavin availability, supporting high-dose B2 as an energy-cofactor therapy.[54] In one case, a man with a persistently red, vascularized nose was given B-complex injections by his doctor and, within hours of the first injection, his nose was no longer red and his previously halting speech became fluent, attributed to the riboflavin content correcting a brain-tissue hypoxia paralleling what was visible in his nose.[55] In another case, a boy with recurring nighttime nosebleeds and violent rages after eating sugary food stopped having both symptoms after a single 10 mg dose of riboflavin, reasoned to have corrected a nighttime dip in blood sugar interacting with a riboflavin-deficient, glucose-wasting metabolism.[56] Already-enlarged and invasive blood vessels from a longstanding deficiency will not necessarily reverse even with prolonged riboflavin supplementation once the overgrowth has become established, and some of the vessel changes responded better to thyroid and DHEA, or to progesterone, by restoring vascular muscle tone rather than correcting riboflavin status.[57]

Riboflavin is part of the mitochondrial respiratory enzymes and is easily destroyed by blue and especially ultraviolet light; when excited by such light it spreads damage to the cytochromes and to polyunsaturated fatty acids, and the other B vitamins suffer when its action is disturbed.[58]

Side/Adverse effects (riboflavin)

[edit]

Synthetic riboflavin is allergenic in some people; natural food sources are the safer option where possible.[59]

Supplements of riboflavin brought on migraine headaches in Peat's own experience, and people with chronic allergies often recovered after stopping vitamin supplements, so foods chosen for nutrient density come first.[60]

Pantothenic acid

[edit]

Vitamin B5 (pantothenic acid) is a water-soluble B-vitamin required for the synthesis of coenzyme A (CoA), a central molecule in energy metabolism and fatty acid synthesis and oxidation. It is widely distributed in foods, and deficiency is rare in well-nourished populations.[61]

Dosing (pantothenic acid)

[edit]
  • Adults (Adequate Intake): 5 mg/day.
  • Pregnancy: 6 mg/day.
  • Lactation: 7 mg/day.[61]
  • No established Tolerable Upper Intake Level (UL), but very high supplemental intakes may cause mild gastrointestinal symptoms.

Structure/Chemical properties (pantothenic acid)

[edit]

Pantothenic acid is composed of pantoic acid linked to β-alanine. It is a small, polar, water-soluble molecule that functions primarily after conversion to coenzyme A and acyl carrier protein (ACP). Because of its water solubility, excess amounts are generally excreted in urine.

Function/Mechanism of Action (pantothenic acid)

[edit]

Pantothenic acid is an essential precursor to coenzyme A (CoA), which is required for the oxidation of carbohydrates, fatty acids, and amino acids. CoA is central to the tricarboxylic acid (TCA) cycle, fatty acid synthesis, cholesterol synthesis, steroid hormone production, and acetylation reactions. Pantothenic acid is also part of acyl carrier protein (ACP), necessary for fatty acid biosynthesis.

Through its role in CoA formation, vitamin B5 directly supports mitochondrial respiration and ATP production, aligning with Ray Peat’s emphasis on oxidative metabolism as the foundation of health.

“The ability to oxidize glucose efficiently is the basis of health, and the B-vitamins are essential for that process.” – Ray Peat

Medical uses/Effects (pantothenic acid)

[edit]

Adequate intake supports energy production, adrenal steroid synthesis, and lipid metabolism. True deficiency is rare but may produce symptoms such as fatigue, irritability, numbness, and gastrointestinal distress. Because of its role in CoA synthesis, pantothenic acid is indirectly involved in stress hormone production and lipid regulation.

Supplemental pantothenic acid is sometimes used for general metabolic support, though strong clinical evidence for specific therapeutic effects in healthy individuals is limited.

The B vitamins act as regulators and facilitators of oxidative energy processes; pantothenic acid stands somewhat apart from the main group but is essential and anti-stress.[62] Vitamin C, vitamin E and pantothenic acid are needed in especially large amounts under stress.[63]

Pantethine and acetaldehyde

[edit]

Pantethine is the disulfide form related to pantothenic acid and coenzyme A. In a small human study, a clinical oral dose of pantethine before alcohol cut the rise in blood acetaldehyde in healthy nonflushing subjects but not in flushing subjects who lacked hepatic low-Km aldehyde dehydrogenase. Blood ethanol concentrations did not change in either group. Pantethine-related metabolites (taurine, pantetheine, coenzyme A, pantothenate) activated ALDH in vitro, and pantethine-treated rats had lower hepatic acetaldehyde after ethanol loading.[64] This is one older trial; it does not establish pantethine as hangover prevention for ALDH2-deficient flushers. See Alcohol.

Side/Adverse effects (pantothenic acid)

[edit]

Pantothenic acid is generally well tolerated. High supplemental doses (typically above 10 g/day) may cause mild gastrointestinal upset or diarrhea. No tolerable upper intake level (UL) has been established due to low toxicity at typical intake levels.

B6

[edit]

Vitamin B6 (pyridoxine and phosphorylated forms) is a cofactor in amino acid, neurotransmitter, and heme metabolism. Mainstream nutrition treats deficiency as rare but linked to neuropathy and homocysteine elevation.

High-PUFA diets and linoleic-acid skin lesions resemble B6 deficiency patterns, and EFA studies often ignored concurrent B6 or biotin lack.[65][66]

Dosing (b6)

[edit]

Peat did not give fixed supplement doses. Liver, eggs, and balanced protein with Gelatin/glycine match his dietary pattern.[67]

Structure/Chemical properties (b6)

[edit]

Pyridoxine, pyridoxal, and pyridoxamine interconvert; pyridoxal phosphate (PLP) is the active coenzyme for decarboxylases and transaminases in mainstream biochemistry.

Function/Mechanism of Action (b6)

[edit]

First-responder pancreatic beta cells depend on endogenous active vitamin B6 synthesis for glucose-stimulated insulin secretion in zebrafish and mouse models.[68] Screening of natural molecules identified pyridoxine (with nicotinamide) as a synergistic activator of muscle stem cells during aging and recovery from injury.[69] Peat cited work linking dietary protein needs to B6 function in vitamin metabolism.[70] B6 participates in homocysteine handling alongside folate and B12 in endotoxin and methylation notes.[71]

The ratio of 4-pyridoxic acid to PLP, a marker of B6 turnover/catabolism rather than intake, tracks metabolic strain separately from dietary B6 status.[72]

PUFA-rich diets increase B6 requirement in animal work described in oils-in-context literature.[73] Similar scaly skin from linoleic excess and from B6 deficiency was used to question "essential fatty acid" dogma in the same article.[74]

Turning dietary B6 into PLP needs riboflavin; in healthy adults, poorer riboflavin status went with lower blood PLP regardless of B6 intake.[75]

Medical uses/Effects (b6)

[edit]

Vitamin B6 deficiency hyperactivated the noradrenergic (stress) system in mice, producing social deficits and cognitive impairment resembling schizophrenia symptoms, mechanistic support for B6 repletion and stress-lowering as a treatment angle in schizophrenia rather than dopamine-blocking antipsychotics alone.[76]

In American adults with type 2 diabetes followed for over a decade, a higher 4-pyridoxic acid/PLP ratio was one of the strongest independent predictors of all-cause mortality; those in the top quartile had roughly 5-fold higher mortality risk than the bottom quartile, after adjustment for demographics, comorbidities, inflammation, kidney function, and nutritional status.[72] This distinguishes B6 turnover from B6 intake as a risk marker in diabetes.

In a cohort of Taiwanese adults aged 65 and over, adequate plasma pyridoxal-phosphate versus deficient levels was associated with about half the all-cause mortality, and the association remained after adjustment for dietary diversity. Higher dietary vitamin B6 intake was also associated with lower mortality before that adjustment. After dietary-diversity adjustment, the intake association was not significant. Residual confounding remains possible in this observational cohort.[77]

Young adults with ADHD had lower blood vitamin B6 and riboflavin than controls, and lower levels tracked more severe symptoms.[78] In an open study without a placebo group, magnesium plus vitamin B6 for two months reduced hyperactivity in children with ADHD.[79]

Mainstream medicine uses B6 for deficiency neuropathy and some nausea protocols. Peat's emphasis is adequate B6 from whole foods when lowering PUFA, not high-dose isolated B6 as a primary strategy.[80] Rosacea writing names B vitamins with riboflavin and thiamine for mitochondrial support.[81]

Vitamin B6 deficiency is one of the causes of seizures, along with lack of glucose, lack of oxygen and magnesium deficiency.[82]

Vitamin B6 steers tryptophan toward niacinamide and away from serotonin; gelatin, which has no tryptophan, works in the same direction.[83][84]

A 1973 Lancet trial tested pyridoxine for depression associated with oral contraceptives.[85]

Fertility and pregnancy

[edit]

A prospective study of women trying to conceive found higher vitamin B6 status associated with a substantially higher chance of conceiving each cycle and a lower risk of early pregnancy loss.[86] Liver is the richest food source of B6. Peat's approach generally favors whole-food sources. Vitamin B6 activates primordial follicles, the earliest and dormant stage of ovarian follicles, via the PI3K/Akt signaling pathway in mouse and human ovarian tissue models; a decline in active primordial follicles is a defining feature of menopause.[87]

Side/Adverse effects (b6)

[edit]

Very high supplemental B6 can cause sensory neuropathy in mainstream reports. See Harm reduction.

Biotin

[edit]

Vitamin B7 (biotin) is a water-soluble vitamin used in carboxylation enzymes (fatty acid synthesis, gluconeogenesis). Mainstream nutrition treats raw egg white avidin binding as the classic deficiency cause.

Scaly skin from high linoleic acid diets can mimic biotin or trace-mineral deficiency, which undercuts simplistic "EFA deficiency" explanations.[88]

Dosing (biotin)

[edit]

No fixed Peat supplement dose. Eggs and liver supply biotin in his typical food lists.[89]

Structure/Chemical properties (biotin)

[edit]

Biotin carries a ureido ring fused to a tetrahydrothiophene ring with a valeric acid side chain; it binds avidin tightly.

Function/Mechanism of Action (biotin)

[edit]

Biotin was grouped with B6 and trace minerals as confounders ignored in early polyunsaturated-fat feeding studies.[90] Adequate biotin supports normal fat metabolism when saturated fats replace unstable seed oils in his dietary framing.[91]

Medical uses/Effects (biotin)

[edit]

In a large UK Biobank prospective cohort of adults without baseline anxiety or depression, higher dietary biotin intake went with lower incidence of anxiety, depression, and their comorbidity than the lowest intake quartile.[92] Risk fell as intake rose up to a moderate threshold, with little further reduction beyond it. Inflammatory markers (including CRP and composite indices) partially mediated the association for anxiety and for combined anxiety or depression, but not for depression alone.

A parallel UK Biobank analysis by the same authors covered dementia: people with more dietary biotin had a meaningfully lower risk of all-cause dementia than those with the least, in the same pattern as above: risk dropped quickly at low intake, then leveled off rather than continuing to fall at higher intake. Part of the association was explained by lower inflammation (prospective cohort).[93]

Mainstream use is deficiency correction (hair loss, dermatitis with avidin excess). Megadose biotin is not the emphasis here; whole foods and lowering PUFA load stay primary.[94]

Side/Adverse effects (biotin)

[edit]

High-dose biotin can interfere with some lab assays in mainstream warnings. See Harm reduction.

Inositol

[edit]

Inositol (sometimes labeled vitamin B8, though the body synthesizes it from glucose and it is not considered a true essential vitamin in modern nomenclature) is a sugar alcohol involved in cell signaling and structure. Peat discussed it less as a nutrient deficiency issue and more as a "stabilizer" molecule that protects cells and proteins from dehydration-type stress.[95]

Dosing (inositol)

[edit]

The OCD trial used 18 g/day.[96] Peat did not give a specific recommended dose of plain inositol in the sources reviewed here.

Structure/Chemical properties (inositol)

[edit]

Inositol is a six-carbon cyclic polyol (cyclohexane-1,2,3,4,5,6-hexol), structurally a cyclic sugar alcohol. Its most common natural form is myo-inositol.

Function/Mechanism of Action (inositol)

[edit]

Peat cited S. J. Webb's studies of bound water showing that inositol helps cells retain water, protecting them against the kind of dehydration-related damage linked to lipofuscin (age pigment) accumulation and impaired energy production.[97] He grouped inositol with potassium, magnesium, vitamin E, and other "orthomolecules" that stabilize cells and proteins against denaturing or dehydrating influences, as distinct from anabolic steroids and other agents that promote protein synthesis directly.[98]

Medical uses/Effects (inositol)

[edit]

A double-blind crossover trial found that 18 g/day of inositol produced significantly lower obsessive-compulsive symptom scores than placebo, and the authors suggested inositol might help across a range of conditions responsive to SSRIs, including depression, panic disorder, and OCD.[99] Separately, Peat specifically distinguished plain inositol from inositol hexanicotinate: when the goal is reducing serotonin formation, he listed progesterone, thyroid, and niacinamide as safe options, explicitly excluding both nicotinic acid and inositol hexanicotinate from that list.[100]

Side/Adverse effects (inositol)

[edit]

Inositol is generally well tolerated even at gram-level doses used in trials; mild gastrointestinal upset has been reported at high doses. Peat's caution was specifically about inositol hexanicotinate as a serotonin-lowering strategy, not about inositol itself.[101]

References

[edit]
  1. ↑ Ray Peat, Nutrition for Women.
  2. ↑ 2.0 2.1 2.2 2.3 Ray Peat, "Nutrition for Women", p. 92
  3. ↑ Ray Peat, "Autonomic Systems," Ray Peat Newsletter, 2006.
  4. ↑ Ray Peat, "Fats: Functions and Malfunctions." "Other lipids, such as a phosphatidylcholine containing two myristic acid groups, can support the enzyme's activity."
  5. ↑ Ask the Herb Doctor: Progesterone vs Estrogen, Listener Questions (Part 2).
  6. ↑ Ray Peat, "Nutrition for Women."
  7. ↑ Ray Peat, "Progesterone in Orthomolecular Medicine."
  8. ↑ Gibbons RD, Hur K, Lavigne JE, Mann JJ. Association Between Folic Acid Prescription Fills and Suicide Attempts and Intentional Self-harm Among Privately Insured US Adults. JAMA Psychiatry. 2022;79(12):1218-1226. https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2796907
  9. ↑ Coppen A, Bailey J. "Enhancement of the antidepressant action of fluoxetine by folic acid: a randomised, placebo controlled trial," J Affect Disord. 2000;60(2):121-30. doi:10.1016/s0165-0327(00)00153-1. PMID 10967371.
  10. ↑ Godfrey PS, Toone BK, Carney MW, Flynn TG, Bottiglieri T, Laundy M, et al. "Enhancement of recovery from psychiatric illness by methylfolate," Lancet. 1990;336(8712):392-5. doi:10.1016/0140-6736(90)91942-4. PMID 1974941.
  11. ↑ Papakostas GI, Petersen T, Mischoulon D, Ryan JL, Nierenberg AA, Bottiglieri T, et al. "Serum folate, vitamin B12, and homocysteine in major depressive disorder, Part 1: predictors of clinical response in fluoxetine-resistant depression," J Clin Psychiatry. 2004;65(8):1090-5. doi:10.4088/jcp.v65n0810. PMID 15323594.
  12. ↑ Du J, Zhu M, Bao H, Li B, Dong Y, Xiao C, Zhang GY, Henter ID, Rudorfer M, Vitiello B. "The Role of Nutrients in Protecting Mitochondrial Function and Neurotransmitter Signaling: Implications for the Treatment of Depression, PTSD, and Suicidal Behaviors," Crit Rev Food Sci Nutr. 2016;56(15):2560-2578. doi:10.1080/10408398.2013.876960. PMID 25365455. PMC4417658. Review.
  13. ↑ Rossignol DA, Frye RE. "Cerebral Folate Deficiency, Folate Receptor Alpha Autoantibodies and Leucovorin (Folinic Acid) Treatment in Autism Spectrum Disorders: A Systematic Review and Meta-Analysis," J Pers Med. 2021;11(11):1141. PMID 34834493.
  14. ↑ Frye RE, Rossignol DA, Scahill L, et al. "Treatment of Folate Metabolism Abnormalities in Autism Spectrum Disorder," Semin Pediatr Neurol. 2020;35:100835. PMID 32892962.
  15. ↑ Ray Peat, "Abnormal Cells in the Uterine Cervix," Collected Works.
  16. ↑ Ray Peat, "Failures of Immunity," Collected Works.
  17. ↑ Ray Peat, "Abnormal Cells in the Uterine Cervix," Collected Works.
  18. ↑ Ray Peat, "Abnormal Cells in the Uterine Cervix," Collected Works.
  19. ↑ Courseault JT, Bix G, et al. "Folate-dependent hypermobility syndrome," Heliyon. 2023. doi:10.1016/j.heliyon.2023.e15387.
  20. ↑ Cao B, Wang DF, Xu MY, et al. "Lower folate levels in schizophrenia: A meta-analysis," Psychiatry Res. 2016;245:1-7. PMID 27521746. Meta-analysis of 20 studies, 1463 cases and 1276 controls.
  21. ↑ Sazci A, et al. "Methylenetetrahydrofolate reductase gene polymorphisms in patients with schizophrenia," Brain Res Mol Brain Res. 2003;117:104-107. PMID 14499487.
  22. ↑ Peerbooms OL, et al. "Meta-analysis of MTHFR gene variants in schizophrenia, bipolar disorder and unipolar depressive disorder: evidence for a common genetic vulnerability?," Brain Behav Immun. 2011;25:1530-1543. PMID 21185933.
  23. ↑ Ramaekers VT, Thöny B, Sequeira JM, Ansseau M, Philippe P, Boemer F, Bours V, Quadros EV. "Folinic acid treatment for schizophrenia associated with folate receptor autoantibodies," Mol Genet Metab. 2014;113(4):307-314. doi:10.1016/j.ymgme.2014.10.002. PMID 25456743.
  24. ↑ Shiwaku H. "Autoantibodies and Inflammation in Schizophrenia," Psychiatry Clin Neurosci. 2025;79(10):611-618. doi:10.1111/pcn.13872. PMID 40693926.
  25. ↑ Blank HM, et al. "Late-life dietary folate restriction reduces biosynthetic processes without compromising healthspan in mice," Life Sci Alliance. 2024. PMID 38260683.
  26. ↑ Ray Peat, "Failures of Immunity," Collected Works.
  27. ↑ Ray Peat, "Abnormal Cells in the Uterine Cervix," Collected Works.
  28. ↑ Ray Peat, email correspondence, "Methylfolate & Methyl B12."
  29. ↑ 29.0 29.1 29.2 Rossignol DA, Frye RE. "Cerebral Folate Deficiency, Folate Receptor Alpha Autoantibodies and Leucovorin (Folinic Acid) Treatment in Autism Spectrum Disorders: A Systematic Review and Meta-Analysis," J Pers Med. 2021;11(11):1141. doi:10.3390/jpm11111141. PMID 34834493.
  30. ↑ 30.0 30.1 Frye RE, Rossignol DA, Scahill L, et al. "Treatment of Folate Metabolism Abnormalities in Autism Spectrum Disorder," Semin Pediatr Neurol. 2020;35:100835. doi:10.1016/j.spen.2020.100835. PMID 32892962.
  31. ↑ Frye RE, Slattery J, Delhey L, et al. "Folinic acid improves verbal communication in children with autism and language impairment: a randomized double-blind placebo-controlled trial," Mol Psychiatry. 2018;23(2):247-256. doi:10.1038/mp.2016.168. PMID 27752075.
  32. ↑ Frye RE, McCarty PJ, Werner BA, et al. "Binding Folate Receptor Alpha Autoantibody Is a Biomarker for Leucovorin Treatment Response in Autism Spectrum Disorder," J Pers Med. 2024;14(1):62. doi:10.3390/jpm14010062. PMID 38248763.
  33. ↑ Ray Peat, email correspondence, "Methylfolate & Methyl B12."
  34. ↑ Ray Peat, email correspondence, "Methylfolate & Methyl B12."
  35. ↑ Ray Peat, "Protective CO2/Aging." "The main mechanisms of epigenetic effects or imprinting are now known to involve methylation and acetylation of the chromosomes (DNA and histones)... The effects of carbon dioxide on many biological processes involving methylation and acetylation of the genetic material suggest that the concentration of carbon dioxide during gestation might regulate the degree to which parental imprinting will persist in the developing fetus."
  36. ↑ Epigenetics, sickness, aging, and changing science
  37. ↑ 37.0 37.1 37.2 Epigenetics, sickness, aging, and changing science, Ray Peat newsletter.
  38. ↑ Hickey SE, Curry CJ, Toriello HV. "ACMG Practice Guideline: lack of evidence for MTHFR polymorphism testing," Genet Med. 2013;15(2):153-156. PMID 23288205.
  39. ↑ Rouphael M, Bitar T, Alarcan H, Gerges P, Sacre Y, Andres CR, Hleihel W. "Exploration of Homocysteine Metabolism and Genetics in Autism Spectrum Disorder," Nutrients. 2025;17(23):3761. doi:10.3390/nu17233761. PMID 41374051.
  40. ↑ Cao B, et al. "Lower folate levels in schizophrenia: A meta-analysis," Psychiatry Res. 2016;245:1-7. PMID 27521746.
  41. ↑ Sazci A, et al. "Methylenetetrahydrofolate reductase gene polymorphisms in patients with schizophrenia," Brain Res Mol Brain Res. 2003;117:104-107. PMID 14499487.
  42. ↑ Sazci A, et al. "Association of the C677T and A1298C polymorphisms of methylenetetrahydrofolate reductase gene with schizophrenia: association is significant in men but not in women," Prog Neuropsychopharmacol Biol Psychiatry. 2005;29:1113-1123. PMID 16084002.
  43. ↑ Peerbooms OL, et al. "Meta-analysis of MTHFR gene variants in schizophrenia, bipolar disorder and unipolar depressive disorder: evidence for a common genetic vulnerability?," Brain Behav Immun. 2011;25:1530-1543. PMID 21185933.
  44. ↑ Ray Peat, "Rosacea, Rhinophyma, Pterygium & Riboflavin—& Varicose Veins," Townsend Letter for Doctors, July 1987, Collected Works.
  45. ↑ Ray Peat, "Rosacea, Rhinophyma, Pterygium & Riboflavin—& Varicose Veins," Townsend Letter for Doctors, July 1987, Collected Works.
  46. ↑ Ray Peat, "Genes, Carbon Dioxide and Adaptation," raypeat.com.
  47. ↑ Ray Peat, "Rosacea, Rhinophyma, Pterygium & Riboflavin—& Varicose Veins," Townsend Letter for Doctors, July 1987, Collected Works.
  48. ↑ Ray Peat, "Rosacea, Rhinophyma, Pterygium & Riboflavin—& Varicose Veins," Townsend Letter for Doctors, July 1987, Collected Works.
  49. ↑ Cimino JA et al. 1987. "Riboflavin Metabolism in the Hypothyroid Human Adult," Proc Soc Exp Biol Med. 1987;184(2):151-153. Six hypothyroid adults aged 59 to 88; 50 µg thyroxine daily for 2 weeks, no vitamins given. doi:10.3181/00379727-184-42459. PMID 3809170.
  50. ↑ Li A, Chen F, Xia Q, et al. "Riboflavin Deficiency Associated With Psoriasis: Insights From Population and Transcriptome," Exp Dermatol. 2025;34(5):e70106. doi:10.1111/exd.70106. PMID 40312926.
  51. ↑ Garg A, Blume SY, Huynh H, et al. "Vitamin B2 and B3 nutrigenomics reveals a therapy for NAXD disease," Cell. 2026;189(9):2648-2662.e19. doi:10.1016/j.cell.2026.01.022. PMID 41747729.
  52. ↑ Nagano T, Awai Y, Kuwaba S, et al. "Riboflavin transporter SLC52A1, a target of p53, suppresses cellular senescence by activating mitochondrial complex II," Mol Biol Cell. 2021;32(21):br10. doi:10.1091/mbc.e21-05-0262. PMID 34524871.
  53. ↑ Carreau C, Lenglet T, Mosnier I, et al. "A juvenile ALS-like phenotype dramatically improved after high-dose riboflavin treatment," Ann Clin Transl Neurol. 2020;7(2):250-253. doi:10.1002/acn3.50977. PMID 32022482.
  54. ↑ Nishiwaki H, et al. "Gut microbes and B vitamins in Parkinson disease," NPJ Parkinsons Dis. 2024. doi:10.1038/s41531-024-00724-z.
  55. ↑ Ray Peat, "Rosacea, Rhinophyma, Pterygium & Riboflavin—& Varicose Veins," Townsend Letter for Doctors, July 1987, Collected Works.
  56. ↑ Ray Peat, "Rosacea, Rhinophyma, Pterygium & Riboflavin—& Varicose Veins," Townsend Letter for Doctors, July 1987, Collected Works.
  57. ↑ Ray Peat, "Rosacea, Rhinophyma, Pterygium & Riboflavin—& Varicose Veins," Townsend Letter for Doctors, July 1987, Collected Works.
  58. ↑ Ray Peat, "Rosacea, inflammation, and aging," raypeat.com.
  59. ↑ Ray Peat, "Rosacea, Rhinophyma, Pterygium & Riboflavin—& Varicose Veins," Townsend Letter for Doctors, July 1987, Collected Works.
  60. ↑ Ray Peat, "Ask the Herb Doctor: Nitric Oxide, Nitrates, Nitrites, and Fluoride", Ask the Herb Doctor, 45:16
  61. ↑ 61.0 61.1 Pantothenic Acid - National Institutes of Health Office of Dietary Supplements
  62. ↑ Ray Peat, "Ask the Herb Doctor: Progesterone vs Estrogen, Listener Questions (Part 2)", Ask the Herb Doctor, 22:18
  63. ↑ Ray Peat, "Nutrition for Women", p. 37
  64. ↑ Watanabe A, Hobara N, Kobayashi M, Nakatsukasa H, Nagashima H. "Lowering of blood acetaldehyde but not ethanol concentrations by pantethine following alcohol ingestion: different effects in flushing and nonflushing subjects," Alcohol Clin Exp Res. 1985;9(3):272-276. PMID 3893199.
  65. ↑ "Oils in Context," Ray Peat article
  66. ↑ "Unsaturated fatty acids: Nutritionally essential, or toxic?," Ray Peat article
  67. ↑ "Gelatin, stress, longevity," Ray Peat article
  68. ↑ Delgadillo-Silva LF, et al. "Vitamin B6 production in beta cells," Sci Adv. 2024. doi:10.1126/sciadv.ado4513.
  69. ↑ Ancel D, Stuelsatz P, et al. "Bioactive nutrients and muscle stem cells," J Clin Invest. 2024. doi:10.1172/jci163648.
  70. ↑ "Oils in Context," Ray Peat article
  71. ↑ "Ray Peat, PhD on Endotoxin"
  72. ↑ 72.0 72.1 Li F, Liu X, Zhao L, et al. "Vitamin B6 Turnover Predicts Long-term Mortality Risk in Patients with Type 2 Diabetes," Curr Dev Nutr. 2024;8(2):102073. doi:10.1016/j.cdnut.2023.102073. PMID 38312433.
  73. ↑ "Oils in Context," Ray Peat article
  74. ↑ "Oils in Context," Ray Peat article
  75. ↑ Jungert A, McNulty H, Hoey L, et al. "Riboflavin Is an Important Determinant of Vitamin B-6 Status in Healthy Adults," J Nutr. 2020;150(10):2699-2706. doi:10.1093/jn/nxaa225. PMID 32805038. Observational study, 407 adults.
  76. ↑ Toriumi K, Miyashita M, Suzuki K, et al. "Vitamin B6 deficiency hyperactivates the noradrenergic system, leading to social deficits and cognitive impairment," Transl Psychiatry. 2021. doi:10.1038/s41398-021-01381-z.
  77. ↑ Huang YC, Lee MS, Wahlqvist ML. "Prediction of all-cause mortality by B group vitamin status in the elderly," Clin Nutr. 2012 Apr;31(2):191-8. doi:10.1016/j.clnu.2011.10.010. PMID 22071291. Taiwanese Elderly Nutrition and Health Survey 1999–2000, 1747 adults followed to 31 December 2008; adequate vs. deficient PLP multivariable-adjusted HR 0.52, 95% CI 0.38–0.71, p for trend <0.0001; highest vs. lowest tertile B6 intake HR 0.74, 95% CI 0.57–0.97, non-significant after dietary-diversity adjustment.
  78. ↑ Landaas ET, Aarsland TI, Ulvik A, Halmøy A, Ueland PM, Haavik J. "Vitamin levels in adults with ADHD," BJPsych Open. 2016;2(6):377-384. doi:10.1192/bjpo.bp.116.003491. PMID 27990293. Case-control study, 133 patients and 131 controls aged 18-40.
  79. ↑ Mousain-Bosc M, Roche M, Polge A, Pradal-Prat D, Rapin J, Bali JP. "Improvement of neurobehavioral disorders in children supplemented with magnesium-vitamin B6. I. Attention deficit hyperactivity disorders," Magnes Res. 2006;19(1):46-52. PMID 16846100. Open study, 40 children with ADHD and 36 controls; no placebo arm.
  80. ↑ "Unsaturated fatty acids: Nutritionally essential, or toxic?," Ray Peat article
  81. ↑ "Rosacea, inflammation, and aging: The inefficiency of stress," Ray Peat article
  82. ↑ Ray Peat, "Epilepsy and progesterone," raypeat.com.
  83. ↑ Ray Peat, email, Serotonin, raypeatemails.com.
  84. ↑ Ray Peat, email, Protein, raypeatemails.com.
  85. ↑ Adams PW, Rose DP, Folkard J, et al. "Effect of pyridoxine hydrochloride (vitamin B 6 ) upon depression associated with oral contraception," Lancet. 1973;1(7809):899-904. doi:10.1016/s0140-6736(73)91359-7. PMID 4123835.
  86. ↑ Ronnenberg AG, Venners SA, Xu X, et al. "Preconception B-Vitamin and Homocysteine Status, Conception, and Early Pregnancy Loss." American Journal of Epidemiology. 2007;166(3):304-312. https://pubmed.ncbi.nlm.nih.gov/17478435/ Conception hazard ratio 2.2 (third vs. lowest quartile); early pregnancy loss odds ratio 0.5 (highest quartile).
  87. ↑ Wen X, et al. "Vitamin B6 promotes the activation of primordial follicles through the PI3K/Akt signaling pathway," J Ovarian Res. 2025.
  88. ↑ "Unsaturated fatty acids: Nutritionally essential, or toxic?," Ray Peat article
  89. ↑ "Gelatin, stress, longevity," Ray Peat article
  90. ↑ "Oils in Context," Ray Peat article
  91. ↑ "Fats, functions and malfunctions.," Ray Peat article
  92. ↑ Kong Y, Xia W, Wang T, Zhang D. "Associations of dietary biotin intake on anxiety and depression: findings from a population-based prospective cohort study," Front Nutr. 2026;12:1745340. doi:10.3389/fnut.2025.1745340. PMID 41550866. PMC12807950. 144,439 adults; median follow-up 14.06 years; quartile 2-4 HR about 0.84-0.86 for anxiety or depression combined; L-shaped dose-response with threshold near 45-48 μg/day.
  93. ↑ Kong Y, Zhong J, Wang T, Zhang D. "Association Between Dietary Biotin Intake and Dementia Risk, Including Alzheimer's Disease: A Prospective Study of 122 959 UK Biobank Participants," Molecular Nutrition & Food Research. 2025;69(22):e70252. doi:10.1002/mnfr.70252. PMID 40914826. Prospective cohort.
  94. ↑ "Unsaturated fatty acids: Nutritionally essential, or toxic?," Ray Peat article
  95. ↑ Ray Peat, "A Biophysical Approach to Altered Consciousness," Collected Works.
  96. ↑ Fux M, Levine J, Aviv A, Belmaker RH, "Inositol treatment of obsessive-compulsive disorder," American Journal of Psychiatry, 1996.
  97. ↑ Ray Peat, "Age Pigment: Cause and Effect of Aging and Stress," Collected Works.
  98. ↑ Ray Peat, "A Biophysical Approach to Altered Consciousness," Collected Works.
  99. ↑ Fux M, Levine J, Aviv A, Belmaker RH, "Inositol treatment of obsessive-compulsive disorder," American Journal of Psychiatry, 1996.
  100. ↑ Ray Peat, "Serotonin Effects in Disease, Aging and Inflammation," Collected Works.
  101. ↑ Ray Peat, "Serotonin Effects in Disease, Aging and Inflammation," Collected Works.