Vitamin B6 Safety & Side Effects
Our assessment
Based on FDA data, the most critical finding for patient safety is that taking high amounts of vitamin B6 from supplements for a year or longer can cause severe nerve damage, leading to loss of control of bodily movements FDA FAERS ↗. This is a serious adverse event that requires immediate attention, though symptoms usually stop when supplement use is discontinued FDA FAERS ↗. The overall risk is dose- and duration-dependent, and the daily upper limits for vitamin B6 include intakes from all sources FDA FAERS ↗.
Safety profile
FDA adverse event data documents that severe nerve damage is the primary serious side effect associated with long-term, high-dose vitamin B6 supplementation FDA FAERS ↗. Other reported side effects include painful, unsightly skin patches, extreme sensitivity to sunlight, nausea, and heartburn FDA FAERS ↗. Data not available for specific report counts for each side effect from the provided FDA data.
How it works
Think of vitamin B6 as a critical cofactor — it supports over 100 enzyme reactions in the body, primarily involved in protein metabolism, cognitive development, and immune function NIH ODS ↗. The body cannot produce it, so it must be obtained from diet or supplements NIH ODS ↗.
Our recommendation
People almost never get too much vitamin B6 from food or beverages, so dietary sources are safe FDA FAERS ↗. However, be cautious with supplements: do not exceed the daily upper limit without medical supervision, especially if taking for longer than one year FDA FAERS ↗. Those taking cycloserine (Seromycin), an antibiotic used to treat tuberculosis, should be aware that vitamin B6 supplements might interact and worsen any seizures and nerve cell damage that the drug might cause FDA FAERS ↗. If you experience loss of coordination, skin changes, or nausea, discontinue use and consult a healthcare provider immediately FDA FAERS ↗.
AI-assisted analysis. Data sourced from NIH ODS and FDA.
Safety Overview
People almost never get too much vitamin B6 from food or beverages. However, taking high amounts of vitamin B6 from supplements for a year or longer can cause severe nerve damage, leading people to lose control of their bodily movements. The symptoms usually stop when they stop taking the supplements. Other symptoms of too much vitamin B6 include painful, unsightly skin patches, extreme sensitivity to sunlight, nausea, and heartburn. The daily upper limits for vitamin B6 include intakes from all sources—food, beverages, and supplements—and are listed below. These levels do not apply to people who are taking vitamin B6 for medical reasons under the care of a doctor. Some experts recommend lower limits for vitamin B6. For example, in 2023 the European Food Safety Authority set an upper limit for vitamin B6 of 12 mg per day for all adults, with lower amounts ranging from 2.2 to 10.7 mg per day for infants and children, depending on age.
Drug Interactions
Yes, vitamin B6 supplements can interact or interfere with medicines that you take. Here are several examples. Vitamin B6 supplements might interact with cycloserine (Seromycin), an antibiotic used to treat tuberculosis , and worsen any seizures and nerve cell damage that the drug might cause. Taking certain epilepsy drugs could decrease vitamin B6 levels and reduce the drugs' ability to control seizures. Taking theophylline (Aquaphyllin, Elixophyllin, Theolair, Truxophyllin, and many others) for asthma or another lung disease can reduce vitamin B6 levels and cause seizures. Tell your doctor, pharmacist , and other health care providers about any dietary supplements and medicines you take. They can tell you if those dietary supplements might interact or interfere with your prescription or over-the-counter medicines or if the medicines might interfere with how your body absorbs , uses, or breaks down nutrients .