Vitamin D and pregnancy outcomes

Area of Science:

• Obstetrics and Gynecology
• Nutritional Science
• Maternal-Fetal Medicine

Background:

• Low vitamin D status, measured by 25-hydroxyvitamin D [25(OH)D], is prevalent among pregnant women.
• Existing research highlights associations between vitamin D levels and adverse pregnancy outcomes.

Purpose of the Study:

• To review recent scientific evidence on maternal vitamin D and pregnancy outcomes.
• Focus on English-language literature published between January 2013 and July 2014.

Main Methods:

• Systematic review of observational studies and randomized controlled trials (RCTs).
• Analysis of meta-analyses examining associations between vitamin D status and pregnancy complications.
• Evaluation of RCTs on vitamin D supplementation during pregnancy.

Main Results:

• Meta-analyses of observational studies show links between low vitamin D and preeclampsia, gestational diabetes, preterm birth, and small-for-gestational age infants.
• Significant heterogeneity exists across studies regarding design, populations, and outcome definitions.
• RCTs demonstrate that vitamin D supplementation improves maternal and neonatal vitamin D status.

Conclusions:

• Low maternal vitamin D status is associated with increased risks of adverse pregnancy outcomes.
• Vitamin D supplementation during pregnancy effectively enhances maternal and neonatal vitamin D levels.
• Large, well-designed multicenter RCTs are necessary to establish the efficacy of vitamin D supplementation in reducing adverse pregnancy outcomes.