Hi, Sharon Weber here from United States Of America. Vitamin B6 is a water-soluble vitamin required for numerous bodily activities such as metabolism, immunological response, and nervous system function. Some evidence exists that vitamin B6 is a supplement to help with PMS symptoms, but more clinical trials are needed to determine if it works. The findings indicate that vitamin B-6 doses of up to 100 mg/day are possibly beneficial in treating premenstrual symptoms and depression.