Elsevier

Fertility and Sterility

Volume 103, Issue 5, May 2015, Pages 1278-1288.e4
Fertility and Sterility

Original article
Effect of vitamin D supplementation during pregnancy on maternal and neonatal outcomes: a systematic review and meta-analysis of randomized controlled trials

https://doi.org/10.1016/j.fertnstert.2015.02.019Get rights and content
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Objective

To assess the effects of vitamin D supplementation during pregnancy on obstetric outcomes and birth variables.

Design

Systematic review and meta-analysis of randomized controlled trials (RCTs).

Setting

Not applicable.

Patient(s)

Pregnant women and neonates.

Intervention(s)

PubMed and 5 other research databases were searched through March 2014 for RCTs evaluating vitamin D supplementation ± calcium/vitamins/ferrous sulfate vs. a control (placebo or active) during pregnancy.

Main Outcome Measure(s)

Measures were: circulating 25-hydroxyvitamin D [25(OH)D] levels, preeclampsia, gestational diabetes mellitus (GDM), small for gestational age (SGA), low birth weight, preterm birth, birth weight, birth length, cesarean section. Mantel-Haenszel fixed-effects models were used, owing to expected scarcity of outcomes. Effects were reported as relative risks and their 95% confidence intervals (CIs).

Result(s)

Thirteen RCTs (n = 2,299) were selected. Circulating 25(OH)D levels were significantly higher at term, compared with the control group (mean difference: 66.5 nmol/L, 95% CI 66.2–66.7). Birth weight and birth length were significantly greater for neonates in the vitamin D group; mean difference: 107.6 g (95% CI 59.9–155.3 g) and 0.3 cm (95% CI 0.10–0.41 cm), respectively. Incidence of preeclampsia, GDM, SGA, low birth weight, preterm birth, and cesarean section were not influenced by vitamin D supplementation. Across RCTs, the doses and types of vitamin D supplements, gestational age at first administration, and outcomes were heterogeneous.

Conclusion(s)

Vitamin D supplementation during pregnancy was associated with increased circulating 25(OH)D levels, birth weight, and birth length, and was not associated with other maternal and neonatal outcomes. Larger, better-designed RCTs evaluating clinically relevant outcomes are necessary to reach a definitive conclusion.

Key Words

Vitamin D
pregnancy
maternal outcomes
neonatal outcomes
meta-analysis

Cited by (0)

F.R.P.-L. has nothing to disclose. V.P. has nothing to disclose. E.M.-H. has nothing to disclose. V.A.B.-Z. has nothing to disclose. P.T. has nothing to disclose. A.D. has nothing to disclose. A.V.H. has nothing to disclose.