Vitamin B6

Is vitamin B6 safe?

At the amounts in food, completely. Adults need only about 1.2 to 1.4 mg a day, and the NHS says a normal diet covers it. The problem is supplements, and the doses they routinely contain. Long-term use of high-dose vitamin B6 can cause peripheral neuropathy: tingling, burning and numbness in the hands and feet, and in bad cases trouble walking. Most people recover after stopping, but some do not.

Regulators have moved sharply on this in the past few years. The European Food Safety Authority (EFSA) cut its adult upper limit to 12 mg a day in 2023. Australia now requires a nerve-damage warning on products above 10 mg and will move products with more than 50 mg a day behind the pharmacy counter from June 2027. Meanwhile, single B6 tablets of 50 or 100 mg are standard in US and online shops. That gap is why B6 scores lower than most vitamins on this site, below vitamin B12 and close to vitamin A.

How much B6 causes nerve damage?

The answer has moved down over time. The first well-known cases involved 1,000 mg a day or more. The Linus Pauling Institute describes cases at under 500 mg, including three older patients who took 600 mg a day for three to ten years.

EFSA's 2023 opinion started from 50 mg a day, a level linked to neuropathy in a case-control study, case reports and vigilance data. It applied a safety factor because symptoms appear sooner at higher doses and later at lower ones, and arrived at 12 mg for adults, including in pregnancy. The limit for children aged 1 to 6 is 3.2 to 4.5 mg. EFSA noted that only regular users of high-dose supplements are likely to exceed it.

The US limit, set in 1998, is still 100 mg. The UK's Department of Health advises no more than 10 mg a day from supplements unless a doctor says otherwise.

What Australia found

Australia's Therapeutic Goods Administration (TGA) has the clearest picture, because it collects reports and lists most supplements as medicines. By 31 October 2025 its adverse event database held 250 reports of peripheral neuropathy and related nerve conditions with vitamin B6 products, 152 of them with high B6 levels recorded. There were 162 more reports of high B6 with vaguer symptoms such as pins and needles.

The TGA's response came in steps:

• March 2022: the warning "Stop taking this medication if you experience tingling, burning or numbness" became compulsory above 10 mg a day, down from 50 mg.
• November 2025: a final decision to make oral products with more than 50 mg and up to 200 mg a day Pharmacist Only Medicines from 1 June 2027. At least 125 products on the market were affected; 116 listed complementary medicines will lose their listings unless evaluated as registered medicines.

The TGA said neuropathy "cannot be excluded" below 50 mg a day, and that people often did not realise B6 was in their product.

Where B6 hides

Most people who get into trouble are not taking a B6 tablet on purpose. The TGA asks doctors to check B-complex vitamins, multivitamins, and magnesium and zinc products, especially when several are taken together, plus fortified foods and drinks such as energy drinks. Labels may name only pyridoxine hydrochloride, pyridoxal 5'-phosphate (P5P) or pyridoxamine.

There is a cruel twist here. The symptoms of too much B6 look like those of too little, and like the nerve pain, cramps and fatigue that magnesium and B-complex products are sold for. Someone with tingling feet may take more.

Interactions with medicines

High-dose B6 can reduce the effect of the anti-seizure drugs phenytoin and phenobarbital, and of levodopa when it is taken without carbidopa (Linus Pauling Institute). Other drugs work the other way and lower B6 levels: isoniazid for tuberculosis, penicillamine and theophylline. Patients on isoniazid are often prescribed B6 to protect their nerves, which is a good reason not to add more on your own. If you take any of these, talk to your doctor or pharmacist before using a B6 product.

How to stay under the limit

1. Add up every product. Check B-complex, multivitamins, magnesium, zinc, "sleep" and "stress" blends, and energy drinks for pyridoxine, pyridoxal or P5P.
2. Aim for 10 to 12 mg a day or less from supplements unless a doctor has prescribed more for a specific reason.
3. Be wary of 50 and 100 mg tablets. Few people need them, and placebo-controlled trials have generally not shown benefits from high doses.
4. Stop and see a doctor if you get tingling, burning or numbness, and bring every supplement bottle with you. A blood test can check your B6 level.
5. A multivitamin at daily-value levels usually supplies 2 mg or less, well within limits.

How we scored it

Organ toxicity (50) and dose safety (55) are the weakest factors: nerve damage is well documented, and common products sit far above the EU limit. Regulatory actions (55) reflect Australia's warnings and rescheduling and EFSA's lower limit. Product quality (72) loses points for hidden and confusingly named B6 rather than contamination, and interactions (80) are limited to a few anti-seizure and Parkinson's drugs.