Effect of Combined Use of Calcium and Vitamin B6 on Premenstrual Syndrome Symptoms: a Randomized Clinical Trial.
In this study of 76 women, premenstrual syndrome was decreased by taking calcium 500 mg and vitamin B6 40 mg twice a day. Taking only vitamin B6 also decreased symptoms, but was not as effective at taking both calcium and vitamin B6. (J Caring Sci. 2016 Mar 1;5(1):67-73.)