Vitamin D Supplementation for the Outcomes of Patients with Gestational Diabetes Mellitus and Neonates: A Meta-Analysis and Systematic Review

Abstract

Background. Prevention and timely treatment of gestational diabetes mellitus (GDM) are important to the prognosis of pregnant women and neonates. We aimed to conduct a meta-analysis to evaluate the effects and safety of vitamin D supplementation on GDM patients and neonates, to provide insights into clinical GDM treatment. Methods. Two authors searched the Medline, PubMed, Cochrane Library, Web of Science, Embase, CNKI, and Wanfang databases for randomized controlled trials (RCTs) on the effects and safety of vitamin D supplementation in GDM patients. The quality of the included RCTs was evaluated according to Cochrane handbook. RevMan 5.3 software was used for statistical analysis. Results. A total of 20 RCTs involving 1682 GDM patients were finally included, of whom 837 received vitamin D supplementation. Vitamin D supplementation in GDM patients increased the serum 25(OH)D level (SMD = 4.07, 95% CI: (2.73, 5.41)) and HDL level (SMD = 0.41, 95% CI: (0.23, 0.58)) and reduced serum LDL (SMD = −0.49, 95% CI: (−0.68, −0.29)), TG (SMD = −0.59, 95% CI: (−1.01, −0.17)), and TC (SMD = −0.67, 95% CI: (−1.19, −0.14)) levels in GDM patients (all $P<0.05$ ). Besides, vitamin D supplementation reduced the risk of premature birth (OR = 0.37, 95% CI: (0.22, 0.62)), hyperbilirubinemia (OR = 0.38, 95% CI: (0.25, 0.58)), and neonatal hospitalization (OR = 0.38, 95% CI: (0.25, 0.58)) of neonates (all $P<0.05$ ). No significant publication bias in synthesized results was found (all $P>0.05$ ). Conclusions. Vitamin D supplementation improves the blood lipid level in GDM patients and reduces adverse neonatal outcomes. The dose and duration of vitamin D supplementation for safety need to be further investigated in future high-quality studies.