Effects of Vitamin D Supplementation on the Follicular Development, Gonadotropins and Sex Hormones Level and Insulin Resistance in Induced Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) as a reproductive disorder disturbs ovarian follicular development, vitamin D stimulated insulin activity and sex hormones levels. This study aimed to examine the effects of vitamin D on the ovarian follicular development, insulin resistance and sex hormones changes in induced-PCOS rats.
Materials & Methods: Forty female Wistar rats were randomly divided into four groups: (1) control, (2) induced PCOS, (3) vitamin D treated non-PCOS (sham group), (4) vitamin D treated PCOS groups. All rats were then sacrificed under anesthesia and ovarian tissue samples were evaluated histomorphometrically. Blood samples were collected for analyzing the serum levels of sex hormones and insulin resistance.
Results: The number of atretic follicles at different stages of development increased in the PCOS ovaries (P<0.001). Vitamin D treatment significantly increased the normality of follicles in PCOS rats (P<0.001). The serum level of follicle-stimulating hormone (FSH) and the estradiol levels significantly increased in PCOS rats, while the testosterone and Luteinizing hormone (LH) levels, glucose, insulin, and insulin resistance levels significantly decreased during vitamin D treatment (P<0.001).
Conclusion: This study indicated that vitamin D treatment may protect ovarian tissue from the negative effect of PCOS by improving insulin activity and gonadotropin levels.