Effects of Vitamin D Supplementation on Metabolic and Endocrine Abnormalities in Polycystic Ovary Syndrome

There is growing evidence suggesting the possible role of vitamin D deficiency in the metabolic and endocrine aberrations associated with the PCOS syndrome. In view of these findings this study was proposed to evaluate the vitamin D levels in women with PCOS and to explore the effect of vitamin D supplementation on clinical, hormonal, and metabolic profile of vitamin D deficient/insufficient PCOS women.

Methods:

The study involved 41 vitamin D deficient/insufficient subjects aged 18–40 years old, with PCOS diagnosed according to the Rotterdam criteria and randomly allocated into 2 groups to take either Metformin treatment plus 4000 IU vitamin D supplementation daily (Group A, n = 20) or Metformin treatment plus placebo treatment (Group B, n = 21) for 24 weeks.

Results:

At the baseline two groups did not differ in their age, BMI, hirsutism score, acne grade and ovarian volumes. The mean Vitamin D levels at the baseline were comparable in two groups with level of 11.2ng/ml in group A and 15.5ng/ml in group B.

After the 24-week intervention, compared to the placebo, group A had significant increase in vitamin D levels as compared to group B (11.2 vs. 36.2ng/ml, p=0.004). Vitamin D supplementation significantly decreased testosterone levels (56.3 vs 42.3ng/ml, P=0.03), fasting plasma glucose (102 vs. 80mg/dl, P=0.05), total cholesterol (172 vs. 158mg/dl, p=0.012), triglycerides (145 vs. 120mg/dl, p=0.05), and LDL cholesterol levels (107 vs. 102mg/dl, P=0.01) in group A compared to baseline. However, in group B no such significant changes were observed. However, a significant decrease in fasting insulin levels (p=0.004), and HOMA-IR (p=0.002) was observed in both groups compared to baseline. MATSUDAINDEX was found to be significantly increased in group A as compared to baseline (p=0.024). Nevertheless, the mean of MATSUDAINDEX did not differ in group B as compared to baseline. BMI, menstrual irregularity, hirsutism score, acne grade and ovarian volume did not differ significantly in both groups as compared to baseline.

Discussion/Conclusion:

In conclusion, there was a significant increase in vitamin D levels in vitamin D supplemented group compared to placebo group. Furthermore, vitamin D supplementation for 24 weeks in vitamin D-deficient women with phenotype B-PCOS reduced insulin resistance and hyperandrogenism, as well improving the lipid metabolism, fasting insulin levels and glucose homeostasis parameters, of patients with PCOS to an extent.