Vitamin B6 reduces anxiety

Vitamin B6 has been tested for anxiety in a small number of trials, and in most of them people taking it did not end up less anxious than people taking a placebo or a comparison product. Among the trials of B6 on its own read for this claim, the one reporting less anxiety gave 100 mg a day of pyridoxine for 30 to 35 days to 265 adults in the UK, mainly students. Anxiety fell mainly in the B6 group, with a smaller fall in the placebo group, but when the change in the two groups was compared directly, the difference was not statistically significant. A 2026 paper by the same researchers analysed the same participants with a different anxiety questionnaire and found no benefit of B6 for anxiety.

Other trials found no benefit. In 211 healthy women in Australia, 75 mg a day for 35 days had no effect on mood, measured with questionnaires that included a tension-anxiety scale. Neither 80 mg a day for 60 days in 60 women with fibromyalgia nor 30 mg added to magnesium, compared with magnesium alone, in 264 stressed adults made a statistically significant difference to anxiety. A 2019 review of trials of supplements that combined B6 with other B vitamins found no effect on anxiety in 562 people. The 100 mg dose is the US upper limit for adults and more than eight times the 12 mg a day upper limit the European Food Safety Authority set for all adults in 2023, and at high doses taken for months, pyridoxine can damage sensory nerves.

In the 2022 trial, anxiety was one of several outcomes, the participants were mainly students, and the authors described the work as exploratory. The tablets were donated by the company Innopure, and the paper prints no funding statement. The authors proposed that high-dose B6 increases GABA signalling, which dampens nerve activity, and they found stronger visual surround suppression, one of the sensory measures they used as markers of it, but no reliable change in the other outcome measures.

In the fibromyalgia trial, anxiety scores improved with both B6 and placebo by similar amounts. In the magnesium trial, anxiety improved in both groups; there was no placebo group, and the study was funded by Sanofi, which makes the magnesium and B6 product tested. B6 has also been tested for premenstrual symptoms: in a 2000 crossover trial of 44 women, no single treatment differed from the others overall, while a planned comparison found that 200 mg of magnesium together with 50 mg of B6 a day reduced anxiety-related premenstrual symptoms. The result for B6 alone in this trial is reported only in the full text, which was not read for this claim.

The two upper limits differ: 100 mg a day in the US and 12 mg a day in Europe since 2023. In a clinical reference on toxicity, sensory nerve damage from pyridoxine usually develops above 1000 mg a day, and there are case reports below 500 mg a day in people taking supplements for months; it usually improves within six months of stopping, and some people do not recover. Vitamin B6 is also in many multivitamins and B-complex products and in some magnesium products, so amounts from several products add up. The US prescribing information for pyridoxine says people treated with levodopa should avoid supplements with more than 5 mg of pyridoxine a day, and that its safety and effectiveness in children have not been established. The US Office of Dietary Supplements notes research indicating that 200 mg a day of pyridoxine, taken for 12 to 120 days, can lower blood levels of the anti-seizure medicines phenytoin and phenobarbital. The European limit of 12 mg a day also applies during pregnancy and breastfeeding.

UK national guidance on generalised anxiety disorder and panic disorder sets out stepped care, offering the least intrusive, most effective intervention first, and does not mention vitamin B6; it asks clinicians to discuss over-the-counter preparations, their potential interactions and the lack of evidence to support their safe use. None of the trials cited here recruited people diagnosed with an anxiety disorder, and none enrolled children. How B6 would sit alongside anxiety treatment, other medicines or pregnancy is a conversation for the reader's clinician.