The Healthspan Map · Nutrient

Vitamin B6

Compiled by Aamir Malik, PhD, Professor of Neuroengineering at Brno University of Technology, from published studies. He is a researcher, not a physician. Last updated 21 August 2026.

Linked to getting too little

Where a shortfall of Vitamin B6 is linked: 16 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Condition or system	Direction	Strength	Evidence type	What was found	Source
Anemia	Eat enough of	Emerging	Review / narrative	Vitamin B6 deficiency can cause sideroblastic anemia (impaired heme synthesis).	B6 & sideroblastic anemia (opens in a new tab)
Anxiety	Eat enough of	Emerging	RCT / meta-analysis	B-vitamin supplementation aids stress/anxiety regulation; supports neurotransmitter synthesis.	Young et al. 2019, Nutrients (opens in a new tab)
Brain fog & memory	Eat enough of	Moderate	Review / narrative	Vitamin B6 (with folate/B12) regulates homocysteine and neurotransmitter synthesis; low B6 is linked to cognitive slowing.	Linus Pauling Institute; homocysteine literature (opens in a new tab)
Brain fog & memory	Eat enough of	Moderate	Review / narrative	Vitamin B6 (with folate/B12) regulates homocysteine and neurotransmitter synthesis; low B6 is linked to cognitive slowing.	Linus Pauling Institute — Vitamin B6 (opens in a new tab)
Chronic fatigue / low energy	Eat enough of	Emerging	Review / narrative	B6 supports neurotransmitter and energy metabolism; deficiency is linked to fatigue and low mood.	Micronutrients for energy/fatigue review (Tardy 2020) (opens in a new tab)
Depression / low mood	Eat enough of	Moderate	Mechanistic	B6 (as PLP) is a cofactor for serotonin, dopamine and GABA synthesis; deficiency causes depression, confusion and irritability.	NIH ODS / systematic review – Vitamin B6 (opens in a new tab)
Depression / low mood	Eat enough of	Moderate	Established clinical	B6 (as PLP) is a cofactor for serotonin, dopamine and GABA synthesis; deficiency causes depression, confusion and irritability.	NIH Office of Dietary Supplements — Vitamin B6 (opens in a new tab)
Headache & migraine	Eat enough of	Emerging	Cohort / observational	Higher dietary vitamin B6 intake is inversely associated with severe headache/migraine; evidence emerging.	Dietary B6/folate-migraine association (via food-migraine review 2024) (opens in a new tab)
Insomnia / poor sleep	Eat enough of	Moderate	Mechanistic	Vitamin B6 is the cofactor converting tryptophan to serotonin and then melatonin; low B6 lowers melatonin.	Melatonin-cofactor review (Peuhkuri 2012) (opens in a new tab)
Peripheral neuropathy	Eat enough of	Moderate	Systematic review	B6 deficiency causes a sensorimotor peripheral neuropathy.	Vitamin B6 & neuropathy (opens in a new tab)
Respiratory infections & airway health	Eat enough of	Emerging	Review / narrative	Vitamin B6 deficiency impairs lymphocyte proliferation and antibody production, weakening defence against infection.	Multivitamin-mineral & respiratory infection (PMC12310427) (opens in a new tab)
Skin, hair, nails & wound healing	Eat enough of	Emerging	Review / narrative	Vitamin B6 deficiency causes seborrheic dermatitis and cheilitis.	B6 & skin (opens in a new tab)
Stress	Eat enough of	Moderate	RCT / trial	Vitamin B6 added to magnesium significantly reduced severe stress in an RCT, enhancing magnesium’s effect.	Magne-B6 RCT (Pouteau et al. 2018) (opens in a new tab)
Tinnitus	Eat enough of	Emerging	Review / narrative	Vitamin B6 is among the micronutrients commonly recommended for tinnitus, though evidence is largely anecdotal.	Micronutrients recommended for tinnitus (opens in a new tab)
Vision problems	Eat enough of	Emerging	Review / narrative	B6, with folate/B12, lowers homocysteine linked to AMD risk.	Retinal/ocular supplements review (PMC9710404) (opens in a new tab)
Weak immunity & chronic inflammation	Eat enough of	Moderate	Review / narrative	Vitamin B6 supports lymphocyte proliferation and Th1 cytokine responses.	Vitamin B6 & immunity (opens in a new tab)

Linked to getting too much

Where an excess of Vitamin B6 is linked: 1 source.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Condition or system	Direction	Strength	Evidence type	What was found	Source
Peripheral neuropathy	Don't overdo	Moderate	Systematic review	Excess B6 (megadose supplements, >=200 mg/day) causes a sensory peripheral neuropathy; keep supplements low.	Vitamin B6 toxicity & neuropathy (opens in a new tab)

The Healthspan Map is part of Fix the Floor, a book by Aamir Malik. About the book