Effectiveness of Vitamin D supplementation in combination with calcium on risk of maternal and neonatal outcomes: A quasi-experimental clinical trial

Abstract Objectives: We examined the effectiveness of combining Vitamin D supplementation with calcium on maternal and neonatal outcomes, as opposed to using Vitamin D supplements alone. Materials and Methods: Pregnant women in their third trimester were divided into two groups. The control group received a daily dose of 1000 IU of Vitamin D, but, the experimental group received a combined daily dosage of 1000 IU of Vitamin D and 500 mg of calcium, until delivery. Results: The women in the Vitamin D + calcium group were less likely to develop gestational diabetes (2.78%; vs. 19.51%; P = 0.0318), preeclampsia (2.78% vs. 26.83%; P = 0.004), newly onset gestational hypertension (11.11% vs. 46.34%; P = 0.001), proteinuria (5.56% vs. 39.02%; P = 0.0004), and impaired glucose tolerance (2.78% vs. 21.95%; P = 0.0163) and had lower blood pressure at 20 th and 39 th weeks of gestation. The newborns in the Vitamin D + calcium group were less likely to experience low birth weight (5.71% vs. 31.58%; P = 0.0066), low birth length (5.71% vs. 44.74%; P = 0.0007), were less likely to be admitted to the neonatal intensive care unit (14.29% vs. 42.11%; P = 0.0105), have a larger head circumference (35.00 vs. 33.63; P < 0.0001), longer gestational age at birth (40.0 vs. 37.56 weeks; P < 0.0001), and higher APGAR scores (9.58 vs. 6.31; P < 0.0001.) compared to Vitamin D group, respectively. Conclusions: Taking Vitamin D and calcium by pregnant women in the third trimester is an effective treatment to decrease maternal, fetal, and neonatal outcomes.