Overview
Vitamin B6, or pyridoxine, is a water-soluble vitamin essential for over 100 enzyme reactions, primarily in protein metabolism. It plays a critical role in neurotransmitter synthesis, red blood cell formation, and immune function. The biologically active form, pyridoxal 5'-phosphate (PLP), serves as a cofactor in amino acid, glucose, and lipid metabolism. Adequate B6 status is associated with optimal cognitive and neurological function, though supplementation trials in older adults have not consistently demonstrated cognitive benefits [1]. While B6, along with B12 and folic acid, effectively lowers homocysteine levels—a potential cardiovascular risk factor—large randomized trials have not shown a reduction in cardiovascular events or depression incidence with long-term supplementation [2][3][4]. A plasma PLP concentration above 30 nmol/L is considered adequate, and many older adults have suboptimal levels, suggesting a need for improved intake or supplementation in at-risk populations [8].
Dosage Guide
Recommended Daily Allowance
For generally healthy individuals
Therapeutic Doses
For treatment of specific conditions
Upper Intake Limit
Maximum safe daily intake
100 mg— Tolerable upper intake level for adults; long-term intake above this may cause sensory neuropathy
Special Forms
Alternative forms for specific needs
Active form; preferred in malabsorption, genetic disorders, or for avoiding high-dose pyridoxine risks
Clinical Notes
- High-dose vitamin B6 (above 100 mg/day long-term) is associated with sensory neuropathy and irreversible nerve damage [8]
- PLP is the preferred form in patients with impaired conversion of pyridoxine (e.g., liver disease, genetic polymorphisms)
- Monitor neurological symptoms (numbness, ataxia) with prolonged high-dose use
- Pregnancy-related nausea regimens typically combine 10-25 mg B6 with doxylamine, under medical guidance
Research
Systematic review found no clear evidence that vitamin B6 supplementation improves cognitive function in randomized trials.
Combination B6, B12, and folic acid supplementation did not reduce cardiovascular events in high-risk women.
Adjunctive B6 (25 mg/day), B12, and folic acid did not significantly improve depression outcomes in older adults on antidepressants.
Long-term supplementation with B6 (50 mg/day), B12, and folic acid did not reduce risk of depression in older women.
Supplementation with B vitamins at ~2.5x RDA for 6 weeks effectively increased blood levels and reduced homocysteine in healthy adults.
Study protocol proposes B vitamin supplementation in ICU patients with COVID-19, but results not yet available.
Nutritional supplement containing B6 (2.5 mg/day) significantly reduced plasma homocysteine in acutely ill older patients.
PLP-based B6 supplements in low weekly doses (50–100 mg) are recommended to maintain adequate B6 status and avoid neurotoxicity.
Products Containing Vitamin B6(6 reports)
Ortho B Complex is a high-potency B-complex supplement delivering 50 mg each of vitamins B1, B2, B3, B5, and B6, along with 200 mcg B12, 1,360 mcg folic acid (B9), 75 mcg biotin, 19 mg choline, and 50 mg inositol. The formulation emphasizes pharmacological doses of B vitamins, particularly those involved in energy metabolism, homocysteine regulation, and neurological function.
BioActive Complete B-Complex is a high-potency B-vitamin supplement designed to support energy metabolism, neurological function, and homocysteine regulation. The formulation features all eight B vitamins at doses that meet or exceed clinically studied levels for key indications, with particular emphasis on B1, B2, B3, B6, B9, and B12 for metabolic and neurological support.
Alpha Brain® is a nootropic dietary supplement formulated to support cognitive function, focus, and mental clarity. The product relies primarily on the Onnit Focus Blend—containing Alpha-GPC, Bacopa extract, and Huperzine A—as its core cognitive-enhancing components, supported by additional blends targeting neurotransmitter balance, stress resilience, and metabolic brain support.
This supplement delivers high-dose vitamin D (25µg/1000 IU) as a primary ingredient, supported by a full B-complex, vitamins C and E. The formulation is designed to support immune function, metabolic health, and antioxidant defense, with clinically relevant dosing of key micronutrients.
HYDROXYCUT HARDCORE LIQUID HEAT is a thermogenic weight management supplement with caffeine and cayenne pepper extract as its primary active ingredients. These compounds are clinically shown to enhance metabolic rate, reduce energy intake, and support fat oxidation. The formulation includes supporting doses of B-vitamins and green coffee bean extract to complement energy metabolism and cardiovascular health.
This multivitamin provides a comprehensive blend of essential vitamins at doses aligned with recommended dietary allowances and evidence-based clinical ranges. Vitamin D, B12, and folate are included at levels shown to support immune, neurological, and cardiovascular health, particularly in at-risk populations.