The effect of vitamin D supplementation on insulin resistance, visceral fat and adiponectin in vitamin D deficient women with polycystic ovary syndrome: a randomized placebo-controlled trial

Introduction: Low plasma 25-hydroxy-vitamin D (25OHD) is associated with polycystic ovary syndrome (PCOS). Vitamin D deficiency may contribute to the development of insulin resistance, visceral fat and low level of adiponectin which are common feature in PCOS women. This study aimed to evaluate the effect of vitamin D supplementation on insulin resistance, visceral fat, and adiponectin in hypovitaminosis D women with polycystic ovary syndrome.Methods: In this randomized, placebo-controlled clinical trial, 44 PCOS women aged 20-38years with plasma 25OHD<20ng/mL were randomized in the intervention or placebo groups and followed for 8weeks. Participants received 50,000IU of oral vitamin D3 once weekly in the intervention group or placebo. The visceral adipose tissue, Insulin resistance (HOMA-IR), HOMA-B, QUICKI, and circulating adiponectin were compared before and after the intervention within groups using paired tests and the mean changes were analyzed between two groups by independent t-test.Results: Of 44 eligible participates, 36 patients (81.8%) completed the study. After 8week intervention, vitamin D supplementation compared to the placebo group significantly decreased fasting plasma glucose (FPG) (7.677.66 versus 1.717.50mg/dL, p=.001) and significantly increased homeostasis model of assessment-estimated B cell function (HOMA-B) (129.76121.02 versus 48.32128.35, p=.014), Adiponectin (5.178.09 versus -5.29 +/- 8.64mg/dL, p=.001), and serum vitamin D level (28.24 +/- 6.47 versus 3.55 +/- 4.25ng/mL, p=.001).Conclusion: Vitamin D supplementation in vitamin D deficient women with PCOS, improved the FPG, HOMA-B, Adiponectin, and serum vitamin D level.