Vitamin B6 Toxicity: Nerve Damage, Upper Limits and High-Dose Supplements
How too much vitamin B6 from supplements can damage nerves, what the upper limits are in the EU, UK and Canada (they differ), and who should check their products.
Content last updated . This page has not been medically reviewed.
Check this first
If you take a vitamin B6 supplement and notice numbness, tingling or loss of feeling in your hands or feet, or trouble with coordination, please talk to a doctor or pharmacist promptly and bring your supplement labels. MedlinePlus lists difficulty coordinating movement, numbness and sensory changes as effects of large B6 doses. [1] The NHS (UK) says the nerve damage usually improves after stopping the supplements, but in a few cases, particularly when large amounts were taken for more than a few months, the effect can be permanent. [2] Do not stop a medicine your doctor prescribed without asking.The short answer
EFSA found no safety concerns about B6 intake from food alone. [3] Harm is documented from long-term high-amount supplements, and the harm is nerve damage (peripheral neuropathy). A key point is that official upper limits differ a lot between countries and bodies, from 10 to 100 mg a day, which is why this page gives each figure with its source and year.Evidence labels used: established nutritional role, evidence of harm, insufficient evidence.
What B6 toxicity is
A 2023 systematic review of 20 articles concluded that higher B6 levels, usually from supplements, may cause a predominantly sensory nerve disorder of the axonal type, and that symptoms improve after pyridoxine is stopped. [4] It concluded that current evidence supports a neurotoxic role of B6 at high levels. [4] A 2021 review of how it happens suggests that high pyridoxine levels may interfere with an enzyme called pyridoxal kinase and disturb signaling in sensory nerve cells, though the exact mechanism has not been proven. [5]The same 2023 review notes that both deficiency and high intake have been described as risk factors for neuropathy, so numbness is not by itself a sign of too little or too much. [4] Please do not guess; a clinician can look at the full picture.
What the NHS says about amounts
| Amount in supplements (UK, NHS 2020) | What the NHS says |
|---|---|
| 200 mg a day or more | Can lead to loss of feeling in the arms and legs (peripheral neuropathy). [2] |
| 10 mg to 200 mg a day | Effect unclear; not enough evidence to say how long these doses can be taken safely. [2] |
| 10 mg a day or less | UK advice: do not take more than 10 mg a day in supplements unless advised by a doctor. [2] |
Official upper limits compared
Upper limits (UL) are the highest daily intakes thought unlikely to cause harm for most people. They are set differently by each body, so one number does not apply everywhere. See RDA, AI, DV and UL.| Body, year and population | Upper limit for vitamin B6 |
|---|---|
| EFSA, EU, 2023: adults including pregnant and breastfeeding women | 12 mg a day. [6] |
| EFSA, EU, 2023: children | 2.2 to 2.5 mg (4 to 11 months), 3.2 to 4.5 mg (1 to 6 years), 6.1 to 10.7 mg (7 to 17 years) a day. [6] |
| EFSA's earlier opinion (Scientific Committee on Food, 2000, published 2006): adults | 25 mg a day (now superseded by the 2023 value). [3] |
| Health Canada DRI table (page dated 2025): adults 19 to 50, pregnancy and lactation | 100 mg a day. [7] |
| NHS, UK, 2020: supplements | 10 mg a day or less unless a doctor advises otherwise. [2] |
| US upper limit (NIH Office of Dietary Supplements) | Could not be verified: that site blocked our download and we do not quote it from memory. |
EFSA says the relationship between excess B6 and neuropathy is well established and is the basis for its UL. [6] EFSA adds that EU populations are unlikely to exceed ULs, except for regular users of food supplements with high doses of B6. [6]
Where high amounts hide
The 2006 EFSA report notes some supplements contain amounts per tablet considerably higher than its upper level, and that it found 2.5% of Irish women aged 18 to 64 exceeding its UL through supplement use. [3] Combined products such as B-complex, multivitamins and "energy" or "stress" formulas can add up with a single-ingredient B6 tablet, so check each Supplement Facts panel. See reading supplement labels, B-complex products and amounts and duplicate ingredients.Normal intake levels, for context
| Source and year | Population | Vitamin B6 |
|---|---|---|
| US RDA via MedlinePlus (reviewed 2025) | Adults 19 to 50; women over 50; men over 50 | 1.3 mg; 1.5 mg; 1.7 mg a day [1] |
| Same | Pregnancy / lactation | 1.9 mg / 2.0 mg a day [1] |
| NHS, UK (2020) | Adults 19 to 64 | About 1.4 mg men, 1.2 mg women a day [2] |
| Health Canada (page dated 2025) | Adults 19 to 50 / pregnancy / lactation | RDA 1.3 / 1.9 / 2.0 mg a day [7] |
The NHS says most people can get all the B6 they need from a varied diet, and the bacteria in the bowel can also make some. [2]
Who should be extra careful
- Pregnancy and breastfeeding: EFSA applies its 12 mg limit to pregnant and breastfeeding women. [6] Ask your midwife or doctor before any B6 supplement: pregnancy and breastfeeding, and see B6 for nausea and PMS.
- Children: limits are much lower than adults'. Do not give adult products; see vitamins for children and teens.
- People who already have neuropathy: a 2023 review says B6 at permitted daily doses has not been proven harmful in people already living with neuropathy, and that no firm evidence shows B6 alone treats it. [4] Speak to the clinician managing the neuropathy.
- Kidney or liver disease, heavy alcohol use: MedlinePlus says B6 deficiency, which is uncommon, can occur in people with kidney failure, liver disease or heavy alcohol use. [1] That is a reason to see a clinician, not to self-treat.
- Medicines and surgery: Proper evidence not found in the sources read for specific B6 interactions. Check with a pharmacist: medication interactions, surgery and procedures.
- Product quality: see quality testing and certifications.
Related
Vitamin B6 profile · The eight B vitamins · Vitamin toxicity: which vitamins have upper limitsFrequently asked questions
How much vitamin B6 is too much?
It depends on the body. EFSA (EU, 2023) sets 12 mg a day for adults; Health Canada lists 100 mg; the NHS (UK) advises no more than 10 mg a day in supplements unless a doctor advises. [6] [7] [2]
Can vitamin B6 nerve damage be reversed?
The NHS says it usually improves after stopping supplements but can be permanent in a few cases. [2] Talk to a clinician.
Can I get too much B6 from food?
EFSA's 2006 report found a wide margin between the upper level and intakes from food alone. [3]
Are the symptoms the same as deficiency?
Both deficiency and high intake have been described as risk factors for neuropathy, so a clinician is needed to tell them apart. [4]
Is the US upper limit the same as the EU's?
We could not verify the US figure because the NIH page was blocked. The EU (12 mg), Canada (100 mg) and UK (10 mg advice) figures all differ. [6] [7] [2]
References
- MedlinePlus Medical Encyclopedia (US National Library of Medicine). Vitamin B6. Review date 1/21/2025. Read 2026-10-23.
- NHS (UK). Vitamins and minerals: B vitamins and folic acid. Page last reviewed 3 August 2020. Read 2026-10-23.
- European Food Safety Authority. Tolerable Upper Intake Levels for Vitamins and Minerals, February 2006 (Scientific Committee on Food opinions: vitamin B6 expressed 19 October 2000; niacin 17 April 2002). Read 2026-10-23.
- Muhamad R, et al. The role of vitamin B6 in peripheral neuropathy: a systematic review. Nutrients 2023;15(13):2823. PMID 37447150. Read 2026-10-23.
- Hadtstein F, Vrolijk M. Vitamin B-6-induced neuropathy: exploring the mechanisms of pyridoxine toxicity. Adv Nutr 2021;12(5):1911-29. PMID 33912895. Read 2026-10-23.
- EFSA Panel on Nutrition, Novel Foods and Food Allergens. Scientific opinion on the tolerable upper intake level for vitamin B6. EFSA Journal 2023;21(5):e08006 (abstract on PubMed). Read 2026-10-23.
- Health Canada. Dietary reference intakes tables: Reference values for vitamins. Page dated 2025-11-19. Read 2026-10-23 through a web-fetch tool.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.