Milajerdi A, Abbasi F, Mousavi SM, et al. - Researchers systematically reviewed prospective cohort studies (with several years of follow-up) examining the correlation between maternal serum vitamin D deficiency or insufficiency and risk of GDM. Performing search through PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar, they identified a total of 29 prospective and nested case-control studies for inclusion in the current systematic review, of which 27 studies had sufficient data for the meta-analysis. Findings revealed that vitamin D deficiency is significantly linked with an increased risk of GDM. Those with a serum vitamin D levels of 40-90 nmol/L were noted to be at the lowest risk of GDM.