Vitamin B6
Pyridoxine / P5P / pyridoxal-5-phosphate · Foundation
Essential, useful in a couple of narrow situations, and the one water-soluble vitamin that reliably causes nerve damage in excess.
What the evidence says
Real evidence for pregnancy-related nausea and a smaller, less consistent literature for premenstrual symptoms. Its popularity in energy and hormone products far exceeds either. Deficiency is uncommon on a normal diet.
What studies used
Requirements sit near 1.3–1.7 mg/day; the tolerable upper limit is 100 mg. Published studies had not established a preferred timing.
Reported from published studies and product labelling — a record of what was used in research, not a recommendation. What is right for you is a conversation with a clinician.
Watch out for
- THE fact this entry exists for: chronic high-dose B6 causes sensory peripheral neuropathy — numbness, tingling and unsteadiness — and it is not always fully reversible. Cases occur at doses widely sold and taken for months
- B6 is in most B-complexes, energy drinks and multivitamins at once, so intake stacks invisibly
Evidence base
established literature
Large human evidence base: several phase 3 or 4 trial reports, plus multiple meta-analyses or systematic reviews.
This letter measures how much human research exists, not whether it works for you — the tier above (Moderate) is the read on quality.
Research (12)
- The Role of Vitamin B6 in Peripheral Neuropathy: A Systematic ReviewNutrients · 2023
- The effects of pyridoxine (vitamin B6) supplementation in nausea and vomiting during pregnancy: a systematic review and meta-analysisArch Gynecol Obstet · 2023
- Vitamin B-6-Induced Neuropathy: Exploring the Mechanisms of Pyridoxine ToxicityAdv Nutr · 2021
- B Vitamins in the nervous system: Current knowledge of the biochemical modes of action and synergies of thiamine, pyridoxine, and cobalaminCNS Neurosci Ther · 2020
- Pyridoxine (vitamin B6) supplementation during pregnancy or labour for maternal and neonatal outcomesCochrane Database Syst Rev · 2015
- Pyridoxine (vitamin B6) supplementation in pregnancyCochrane Database Syst Rev · 2006
- Pyridoxine (vitamin B6) supplementation in pregnancyCochrane Database Syst Rev · 2000
- Problematic rise of vitamin B6 supplementation overuse and potential risk to bariatric surgery patientsNutrition · 2022
- Preventing Vitamin B6-Related NeurotoxicityAm J Ther · 2022
- Vitamin B6: deficiency diseases and methods of analysisPak J Pharm Sci · 2013
- Revisiting the evidence for neuropathy caused by pyridoxine deficiency and excessJ Clin Neuromuscul Dis · 2014
- Drug-pyridoxal phosphate interactionsQ Rev Drug Metab Drug Interact · 1982
Turn Vitamin B6 into a plan that's yours
The info above is free. Membership makes it personal, the Coach answers questions about your exact stack, the Stack tracks it for you, and the Verified Sources shows you how to vet what you buy.
- ✓ AI Coach, ask anything about your stack. It does the dosing math, flags interactions, and tells you what to do next.
- ✓ Personal Stack, save your protocol, track it across devices, log doses, get a heads-up before a vial runs out.
- ✓ Verified Sources, the vetted reference for checking quality and sourcing, members only.
Cancel anytime · or save with $59.99/yr · Coach + Stack included