Effect of vitamin D supplementation on polycystic ovary syndrome: A meta‑analysis

Abstract

The aim of the present meta‑analysis was to evaluate the effect of vitamin D supplementation on patients with polycystic ovary syndrome (PCOS). A literature search was performed to identify all of the relevant studies comparing the effect of vitamin D supplementation with placebo in PCOS patients, in the PubMed, Embase and Web of Science databases. All statistical analyses were performed on case‑control studies using Review Manager 5.3 software, provided by the Cochrane Collaboration. A total of 11 studies involving 483 participants were included in the current meta‑analysis. Vitamin D supplementation appeared to lead to an improvement in the levels of total testosterone [weighted mean differences (WMD) = ‑0.10, 95% CI (‑0.18, ‑0.02)], homeostasis model assessment of insulin resistance [WMD = ‑0.44, 95% CI (‑0.86, ‑0.03)], homeostasis model assessment of β‑cell function [WMD = ‑16.65, 95% CI (‑19.49, ‑13.80)], total cholesterol [WMD = ‑11.90, 95% CI (‑15.67, ‑8.13)] and low‑density lipoprotein‑cholesterol [WMD = ‑4.54; 95% CI (‑7.29, ‑1.80)]. The results failed to show a positive effect of vitamin D supplementation on the body mass index, dehydroepiandrosterone sulfate, triglyceride levels or high‑density lipoprotein‑cholesterol. In conclusion, the data from the available randomized controlled trials (RCTs) suggested vitamin D supplementation reduced insulin resistance and hyperandrogenism, as well improving the lipid metabolism of patients with PCOS to an extent. Further high‑quality RCTs from a variety of regions in the world are required to determine the effectiveness of vitamin D supplementation in PCOS patients, and to determine a suitable dose and unit of vitamin D.