Vitamin D has a crucial role in female reproduction, possibly through its effects on calcium homeostasis, cyclic sex steroid hormone fluctuations, or neurotransmitter function. We have assessed the effects of vitamin D supplementation on dysmenorrhea and premenstrual syndrome (PMS) in adolescents. In this study, 897 adolescent girls living in Mashhad and Sabzevar, Iran, received nine high-dose vitamin D supplements (as 50,000 IU/week of cholecalciferol) and were followed up over 9 weeks. We evaluated the effect of vitamin D supplementation on individuals in four categories: those with only PMS; individuals with only dysmenorrhea; subjects with both PMS and dysmenorrhea and normal subjects. The prevalence of PMS after the intervention fell from 14.9% to 4.8% (p < .001). Similar results were also found for the prevalence of subjects with dysmenorrhea (35.9% reduced to 32.4%), and in subjects with both PMS and dysmenorrhea (32.7% reduced 25.7%). Vitamin D supplementation was associated with a reduction in the incidence of several symptoms of PMS such as backache and tendency to cry easily as well as decrement in pain severity of dysmenorrhea (p < .05). High dose vitamin D supplementation can reduce the prevalence of PMS and dysmenorrhea as well as has positive effects on the physical and psychological symptoms of PMS.
Keywords: Vitamin D supplementation; dysmenorrhea; menstrual cycle; premenstrual syndrome.