Vitamin D supplementation in the treatment of polycystic ovary syndrome: A meta-analysis of randomized controlled trials.

BACKGROUND

Vitamin D level is closely associated with the development of polycystic ovary syndrome (PCOS). We aimed to systematically evaluate the effects of vitamin D supplementation on patients with PCOS, to provide reliable evidence to the clinical treatment of PCOS.

METHODS

We searched PubMed, Medline, EMbase, Cochrane Library, Web of Science, WanFang, China national knowledge infrastructure(CNKI) and Weipu databases for randomized controlled trials (RCTs) on vitamin D supplementation for the treatment of PCOS. Two reviewers independently screened literature, extracted data and evaluated the risk of bias of included RCTs. RevMan 5.3 software was used for meta-analysis.

RESULTS

13 RCTs with 840 PCOS patients were included finally. Meta-analyses indicated that vitamin D supplementation increase the serum vitamin D level[mean difference(MD) = 17.81, 95% confidence interval(CI) (10.65, 24.97)] and endometrial thickness [MD = 1.78, 95%CI (0.49, 3.06), P = 0.007], reduce the serum hs-CRP [MD = -0.54, 95%CI (-1.00, -0.08)], parathyroid hormone[MD = -14.76, 95%CI (-28.32, -1.19)], total cholesterol[MD = -12.00, 95%CI (-18.36, -5.56)] and total testosterone level [MD = -0.17, 95%CI (-0.29, -0.05)] (all p < 0.05). No significant differences in the SHBG level [MD = 1.33, 95%CI (-2.70, 5.36)] and mF-G score [MD = 0.04, 95%CI (-0.79, 0.86)] between vitamin D and control group were found (all p > 0.05). Egger's tests showed that there were no publication biases in every synthesized result (all P > 0.05).

CONCLUSION

Vitamin D may be helpful to improve the endocrine and metabolism-related indexes in patients with PCOS. More high-quality studies with larger sample size are warranted to further evaluate the role of vitamin D supplementation in patients with PCOS.