Introduction: Insulin resistance is one of the most common features of polycystic ovary syndrome, and some studies suggest that vitamin D deficiency may have role in insulin resistance.
Objective: To study the effect of vitamin D supplementation on the clinical, hormonal and metabolic profile of the PCOS women.
Study design: Randomized, placebo-controlled, interventional, double-blind study.
Materials and methods: PCOS women were evaluated and enrolled after considering inclusion and exclusion criteria. They were randomized by block randomization with sealed envelope system done in two groups. In the study group (n = 25), patients were supplemented with vitamin D 60,000 IU weekly for 12 weeks, whereas control group (n = 25) was given placebo weekly for the same period. Both the groups were compared pre- and post-supplementation for variables like clinical profile, biochemical profile and metabolic profile. Statistical analysis was performed by the SPSS program for Windows, version 10.1 (SPSS, Chicago, IL).
Result: In the study (n = 50), PCOS patients were enrolled; 34 patients (68%) were vitamin D deficient (≤20 ng/ml) out of which 10 patients (29%) were severely deficient (<10 ng/ml). Twelve patients (24%) were vitamin D insufficient showing high prevalence of vitamin D deficiency in the PCOS women. The difference in mean serum fasting glucose pre- and post-supplementation of vitamin D in study group was found to be statistically significant with p value of 0.041. There was significant difference seen in insulin resistance (IR) (2.38 ± 4.88-1.00 ± 0.58, p = 0.003), serum fasting insulin (10.34 ± 20.00-5.00 ± 3.25, p = 0.021), and increase in insulin sensitivity determined by QUICKI (0.37 ± 0.04-0.394 ± 0.009, p = 0.001) after supplementation with vitamin D.
Conclusion: The study concluded that there was a beneficial effect of vitamin D supplementation on ovulatory dysfunctions and blood pressure. Post-supplementation, there were decrease in insulin resistance and increase in insulin sensitivity. In the study decreased serum fasting insulin level and fasting blood sugar after vitamin D supplementation suggest underlying role of vitamin D in glucose homeostasis.
Keywords: Glucose homeostasis; Insulin resistance; PCOS; Vitamin D.