The effect of vitamin D supplementation on the androgenic profile in atients with olycystic ovary syndrome: A systematic review and meta-analysis of clinical trials

Background: It is suggested that vitamin D status is associated with androgenic profile in women with polycystic ovarian syndrome (PCOS). Although several clinical trials are known in this regard, the results were inconsistent.Objective: Therefore, this study was aimed to conduct a systematic review and meta-analysis of published clinical trials to elucidate the possible effect of vitamin D supplementation on the androgen levels in adult females with PCOS.Materials and Methods: PubMed, SCOPUS, and Google Scholar were searched to identify related articles published up to January 2017. Mean ± standard deviation (SD) of changes in serum total testosterone, sex hormone binding globulin (SHBG), and free testosterone were extracted to calculate Hedges’ g to be used as effect size for meta-analysis. DerSimonian and Liard random effects model was incorporated to summarize the effects. Six clinical trials with 183 participants aged 18-41 yr with follow-up period between 3-24 wk were included.Results: Our analysis revealed that vitamin D supplementation significantly reduces total testosterone (Hedges’ g=-0.32, 95% CI: -0.55 to -0.10; p=0.005); this effect remained significant in single group trials after subgroup analysis. Vitamin D supplementation did not affect serum free testosterone (Hedges’ g=-0.21, 95% CI: -0.44 to 0.079; p=0.08) or SHBG levels (Hedges’ g=0, 95% CI, 0.22-0.22; p=0.98).Conclusion: The present systematic review and meta-analysis revealed that vitamin D supplementation might significantly affect serum total testosterone while it is not effective in improving other markers of androgenic profile. Future double-blind, placebo-controlled clinical trials are highly recommended.

Keywords:

Vitamin D , Androgens , Polycystic ovary syndrome , Systematic review , Meta-analysis