Effect of Vitamin D Supplementation on Fertilization Outcomes: A Trial Sequential Meta-Analysis of 5 Randomized Controlled Trials.

Despite numerous studies indicating an imperative role of vitamin D for reproduction, the importance of vitamin D supplementation on fertilization (IVF) outcomes remains controversial. We therefore performed this meta-analysis to investigate the IVF outcomes of vitamin D supplementation in infertile women with vitamin D deficiency. We systematically searched PubMed, Embase and the Cochrane library for identifying all relevant studies published before August 2021.