A randomized double-blind crossover trial was conducted to study the effects of pyridoxine (vitamin B6) at a dose of 50 mg per day on symptoms characteristic of the premenstrual syndrome. Sixty three women aged 18-49 years, identified by means of a general practice based survey of menstrual patterns in the community, entered the trial. All of the women had noticed moderate to severe premenstrual symptoms during the previous year. The women kept a daily menstrual diary which graded the severity of nine individual symptoms from zero to three. After completing a diary for an initial month the women were randomized to receive either drug or placebo for three months, after which the treatments were crossed over for a further three months. Thirty two women completed the full seven months of the study. In these women a significant beneficial effect (P less than 0.05) of pyridoxine was observed on emotional type symptoms (depression, irritability and tiredness). No significant effect was observed on premenstrual symptoms of any other type.
PIP: Researchers initiated a randomized double blind crossover trial as part of a community based postal survey of menstrual patterns of 68 women in England. Each woman jotted down daily the severity of symptoms (e.g., depression, headache, etc.). After this 1st study cycle and being randomly assigned to the pyridoxine or placebo group, they either took 50 mg/day of pyridoxine or placebo tablets for 3 months. At the end of 3 months, they followed the other treatment. 37 women completed 6 months and only 32 completed the full 7 months. The results of the study show pyridoxine to significantly affect emotional type symptoms (depression, irritability, and tiredness [p.05]), but not somatic (headache, breast discomfort, swollen abdomen, swollen hands or feet) or menstrual (stomach cramps, backache, other) symptoms. Women who took oral contraceptives (OCs) had nonsignificant higher adjusted premenstrual symptom scores, particularly for emotional type symptoms, during both pyridoxine and placebo months that did those who did not take OCs. This study was complicated by a placebo effect. It revealed a significant decrease in the level of all symptom scores from the 1st month to the 4th month by a mean of 57% (p=.001) when the women took the placebo initially. Emotional type symptoms decreased by 69% (p.05), somatic type by 52% (p.05), and menstrual type nonsignificantly by 15%. On the other hand, when women took the placebo after taking pyridoxine for a month, the combined level of all symptom scores only increased 37% on average (nonsignificant). Based on the results of this study, pyridoxine appears to alleviate premenstrual depression. Further research is needed to confirm the results of this and other similar studies.