While excess Vitamin B6 will usually be excreted in the urine, taking supplements containing high amounts (300 mg or higher) for over a year can result in severe nerve damage. Symptoms usually stop when individuals stop taking such high amounts.
Vitamin B6 is naturally found in some foods and is added to others. It is also available as a supplement. Foods that are naturally rich in Vitamin B6 include poultry, fish and organ meats; Americans get the bulk of their B6 from potatoes, other starchy vegetables and fruit (aside from citrus).
The body absorbs Vitamin B6 in the small intestine. While a true deficiency is rare, those who are dependent on alcohol or eat a plant-based diet may not be getting or absorbing enough.
Vitamin B6 supplements are recommended by the American College of Obstetricians and Gynecologists for nausea and vomiting during pregnancy.
While the research is still in the early stages, taking high doses of Vitamin B6 supplements has been found to significantly reduce feelings of stress, anxiety, and depression. A study published in 2022 in the journal Human Psychopharmacology looked at 478 young adults with self-reported anxiety and/or depression. The double‐blind study investigated the effects of supplementation for one month with a high‐dose of B6 (100 mg as pyroxidine hydrochloride) or B12 (1000 μg as methylcobalmin), compared to placebo. Vitamin B6 “reduced self‐reported anxiety and induced a trend towards reduced depression,” while vitamin B12 supplementation “produced trends towards changes in anxiety and visual processing.”
Research is mixed on whether taking B6 supplements impacts health beyond the nutrient’s essential functions. Certain B vitamins, including B6, may help lower levels of the amino acid homocysteine, to help reduce the risk of cardiovascular disease. Low levels of B6 in the blood are associated with certain types of cancer. In older adults, higher levels of Vitamin B6 in the blood is associated with better memory, but there’s no proof that supplementing improves cognitive function.
