Effects of Calcium-vitamin D and Calcium alone on Pain Intensity and Menstrual Blood Loss in Women with Primary Dysmenorrhea: A Randomized Controlled Trial

Abstract

Abstract: Background & objective: There is limited evidence on effectiveness of calcium and vitamin D on dysmenorrhea. Because of the limited number of studies with some contradictory results in this area, and no reports of adverse effects caused by the intervention, we aimed to determine the effects of combined calcium-vitamin D and calcium-alone on pain intensity and menstrual blood loss (as primary outcomes), and on quality of life, satisfaction with treatment, and analgesic (ibuprofen) intake (as secondary outcomes) in women with primary dysmenorrhea. Material & methods: This randomized placebo-controlled trial with three parallel arms was conducted on 85 single students aged 18 to 32 years living in all three female dormitories of Tabriz University of Medical Sciences, Tabriz-Iran. Participants were randomized into three groups; receiving one tablet/day of 1000 mg calcium + 5000 IU vitamin D3, calcium-alone 1000 mg, or matched placebo, from 15th cycle day until menstrual pain disappearance in the following cycle, for three cycles. Pain intensity and menstrual blood loss were assessed one cycle before-, three cycles under-, and one cycle following-intervention using 10-cm visual analogue scale and pictorial blood loss assessment chart, respectively. The groups were compared using repeated measures ANOVA. Results: Time after intervention and interaction of time with group had no significant effects on the outcomes. Compared to the placebo group, mean pain intensity was lower in the both calcium-vitamin D (adjusted difference -0.7, 95% confidence interval -1.6 to 0.3) and calcium-alone (-1.6, -2.6 to -0.6) groups, but the difference was statistically significant only in the calcium-alone group. Menstrual blood loss was not significantly different in the either calcium-vitamin D (-7.7, -32.0 to 16.7) or calcium-alone (-8.3, -33.0 to 16.5) groups compared to placebo. Conclusion: Intake of the calcium-alone was effective in reducing menstrual pain intensity. The results could not indicate significant effects of calcium-vitamin D on the pain or any of the interventions on menstrual blood loss