Vitamin B6 is water-soluble, which usually means a surplus is passed in urine and excess is not a concern. B6 is the important exception, and the reason it deserves its own page.
Taken at high doses over a prolonged period, vitamin B6 can damage peripheral nerves. The characteristic effect is numbness, tingling or burning in the hands and feet, sometimes with unsteadiness. It usually improves after stopping, but it does not always fully reverse, which makes recognising it early genuinely worthwhile.
This is not a reason to avoid B6 at ordinary amounts. It is a reason not to take high-dose B6 indefinitely without a reason.
Common side effects reported with this supplement or ingredient
At ordinary amounts, side effects are uncommon. Occasionally nausea, stomach upset or headache.
Signs of too much, developing over months rather than days:
- Numbness, tingling or a burning sensation in the hands and feet, usually starting at the extremities
- Clumsiness or unsteadiness on the feet
- Reduced sensation, or difficulty with fine movements
These are easy to attribute to something else, which is exactly the problem. Anyone with new tingling in the hands or feet who takes supplements should have their B6 intake reviewed as part of working out the cause.
Possible interactions with medicines, chronic conditions or pregnancy
B6 can reduce the effect of levodopa used in Parkinson’s disease when taken without the usual companion medicine. It also interacts with some epilepsy medicines. Mention it if you take either. See levodopa side effects.
B6 is sometimes recommended in pregnancy for nausea, at specific amounts and on advice. That is a different situation from taking a high-dose product yourself.
Who should speak to a healthcare professional before using it?
Anyone taking high-dose B6 for longer than a short period, anyone who already has nerve symptoms or a condition affecting nerves such as diabetes, and anyone taking several products that each contain it.
Dose, product-quality and stacking risks
B6 appears in a surprising number of products, which is how intake creeps up without anyone choosing a high dose: B-complex supplements, multivitamins, energy formulas, products marketed for premenstrual symptoms, stress formulas and some fortified drinks.
Add the amounts across everything you take. That total, not any single product, is what matters. See taking too many supplements.
Supplements in South Africa are regulated as complementary medicines, and the checks applied are not the same as those for prescription medicines. Strength and content can vary between products. See how supplements are regulated in South Africa.
When to stop and get medical advice
Stop and seek medical advice promptly for new numbness, tingling, burning or unsteadiness, particularly in the hands and feet, and take all your supplements with you so the total can be calculated.
Early recognition matters here more than with most supplement effects, because the recovery is better the sooner intake stops. Do not wait to see whether it settles.
Report it, with the products and amounts involved. See reporting a supplement side effect.
Related supplement safety guides
- Supplement side effects
- Taking too many supplements
- Supplement and medicine interactions
- When to see a doctor about a supplement
- Report a supplement side effect
See also vitamin B complex side effects and medicines causing numbness and tingling.
Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.