This study intends to adopt a randomized controlled study design, and randomly divide pregnant women at high risk of GDM into intervention group (VitD3:1600 IU/ day) (n=800) and control group (placebo:2 tablets/day) (n=800) until the end of delivery. The risk of GDM in pregnant women of the two groups was compared, the preventive effect of high-dose VitD supplementation during pregnancy on different subtypes of GDM was determined, and the effects of VitD supplementation on VitD nutritional status during pregnancy and birth outcome and health of offspring were explored, so as to provide evidence-based basis for rational VitD supplementation during pregnancy.
This study was a double-blind multicenter randomized controlled study.