Calcium plus vitamin D supplementation affects pregnancy outcomes in gestational diabetes: randomized, double-blind, placebo-controlled trial

Abstract

Objective: The present study was designed to assess the effects of Ca + vitamin D supplementation on pregnancy outcomes in women with gestational diabetes mellitus (GDM). Design: A randomized, double-blind, placebo-controlled trial was conducted among sixty women with GDM. Participants were divided into two groups to receive Ca + vitamin D supplements or placebo. Individuals in the Ca + vitamin D group (n 30) received 1000 mg Ca/d and two pearls containing 1250 mu g (50 000 IU) of cholecalciferol (vitamin D-3) during the intervention (one at study baseline and another at day 21 of the intervention); those in the placebo group (n 30) received two placebos of vitamin D at the mentioned times and placebos of Ca every day for 6 weeks. Pregnancy outcomes were determined. Setting: A urban community setting in Arak, Iran. Subjects: Sixty women with GDM and their newborns, living in Arak, Iran were enrolled. Results: Women treated with Ca + vitamin D had a significant decrease in caesarean section rate (23.3 v. 63.3, P = 0.002) and maternal hospitalization (0 v. 13.3, P = 0.03) compared with those receiving placebo. In addition, newborns of GDM women randomized to Ca + vitamin D had no case of macrosomia, while the prevalence of macrosomia among those randomized to placebo was 13.3 (P = 0.03). Lower rates of hyperbilirubinaemia (20.0 v. 56.7, P = 0.03) and hospitalization (20.0 v. 56.7, P = 0.03) were also seen in the supplemented group of newborns than in the placebo group. Conclusions: Ca + vitamin D supplementation for 6 weeks among pregnant women with GDM led to decreased caesarean section rate and maternal hospitalization, and decreased macrosomia, hyperbilirubinaemia and hospitalization in newborns.