Two hundred seventy-eight Iranian girls (aged 15-17 years) with primary dysmenorrhea were randomly assigned to receive, in double-blind fashion, 200 IU of vitamin E (type not specified) twice a day or placebo, beginning 2 days before the expected start of menstruation and continuing through the first 3 days of bleeding. Treatment was continued for a total of 4 consecutive menstrual periods. The median pain score (on a scale of 0-10, with 10 being the worst) at 2 months was 3 in the vitamin E group and 5 in the placebo group (p < 0.001). At 4 months, the respective values were 0.5 and 6 (p < 0.001). The median duration of pain at 2 months was 4.2 hours in the vitamin E group and 15.4 hours in the placebo group (p < 0.001). At 4 months, the respective values were 1.6 and 16.7 hours (p < 0.001). The mean amount of blood loss was significantly less at 2 months (-23%; p < 0.001) and 4 months (-34%; p < 0.0001) in the vitamin E group than in the placebo group.

Comment: Women with dysmenorrhea have relatively high concentrations of prostaglandin F2alpha in menstrual fluid, and suppression of prostaglandin synthesis is an established treatment for dysmenorrhea. Vitamin E inhibits the release of arachidonic acid and the conversion of arachidonic acid to prostaglandins via actions on phospholipase A2 and cyclooxygenase, respectively. The results of this study suggest that vitamin E supplementation can reduce both the pain of primary dysmenorrhea and the amount of menstrual blood loss. Whether or not the results of this study from Iran would apply to those consuming a western diet was not addressed in this study. However, an earlier study showed that vitamin E reduced the symptoms of dysmenorrhea in British college students (Lancet 1955;1:844-847).

Ziaei S, et al. A randomised controlled trial of vitamin E in the treatment of primary dysmenorrhoea. BJOG 2005;112:466-469.