Effects of curcumin supplementation on vitamin D levels in women with premenstrual syndrome and dysmenorrhea: a randomized controlled study

Background Vitamin D has an established role in female reproduction. There is also evidence for an association between vitamin D levels and menstrual problems such as premenstrual syndrome (PMS) and dysmenorrhea. Curcumin, is a bioactive polyphenol constituent of turmeric, that can potentially interact with vitamin D receptors and its molecular targets. This study evaluated the effects of curcumin on vitamin D levels in young women with PMS and dysmenorrhea. Methods In this randomized, triple-blind, placebo-controlled trial, women with PMS and dysmenorrhea were divided randomly into experimental and control groups to receive one capsule (500?mg of curcuminoid+?5?mg piperine, or placebo) daily, from approximately 7?days before until 3?days after menstruation for three consecutive menstrual cycles. Serum vitamin D levels, renal function, and liver enzymes were also measured before and after intervention. Results A total of 76 subjects (38 in each group) were recruited into the trial. Curcumin significantly increased the median (IQR) serum levels of vitamin D [from 12.8?ng/ml (7.0–24.6) to 16.2?ng/ml (6.4–28.8); P?=?0.045], compared with placebo [from 18.6?ng/ml (2.2–26.8) to 21.3?ng/ml (5.2–27.1); P?=?0.17]. Serum levels of aspartate aminotransferase and direct bilirubin were reduced by the end of trial in the curcumin group (p??0.05). Finally, no significant differences in levels of fasting blood glucose were detected between curcumin and placebo groups. Conclusion Curcumin supplementation in women with PMS and dysmenorrhea led to a significant improvement of vitamin D, liver function enzyme test, but did not affect blood glucose. Trial registration The trial was registered on Iranian Registry of Clinical Trials registry (Trial ID: IRCT20191112045424N1 on 23 January 2020; available at https://www.irct.ir).