Vitamin D during pregnancy linked to improved infant outcomes : JAMA

Vitamin D supplementation during pregnancy may reduce the risk of small for gestational age (SGA) and improve infant growth without risk of fetal or neonatal mortality or congenital abnormality, according to a meta-analysis published in the journal JAMA Pediatrics.

The study was conducted by Wei Guang Bi, from the University of Montréal, Montréal, Quebec, Canada, and colleagues to determine the effects of vitamin D supplementation during pregnancy on growth, morbidity, and mortality of the offspring through systematical review of studies.

Low level of maternal vitamin D is common during pregnancy and is a public health issue worldwide. Vitamin D is a fat-soluble nutrient and prohormone that has a role in calcium absorption, metabolism, and bone health and nonclassic actions that may affect various other aspects of health. Its low-level status during pregnancy may have long-term effects on offspring health outcomes. Sufficient concentrations of the vitamin are needed during pregnancy to address the increased demand for fetal development and growth.

During the past few decades, emerging randomized clinical trials (RCTs) have assessed the effect of its vitamin D supplementation during pregnancy on maternal, neonatal, infant, or child outcomes. However, the results of the RCTs are inconsistent. There is a lack of evidence from systematic reviews and meta-analyses to evaluate the association between its supplementation during pregnancy and offspring growth, morbidity, and mortality.

For the study, the researchers independently extracted data, and the quality of the studies was assessed. Summary risk ratio (RR), risk difference (RD) or mean difference (MD), and 95% CI were calculated using fixed-effects or random-effects meta-analysis.

Key Findings:

• Vitamin D supplementation during pregnancy was associated with a lower risk of SGA without risk of fetal or neonatal mortality or congenital abnormality.


• Neonates with prenatal vitamin D supplementation had higher 25(OH)D levels, calcium levels, and weight at birth, 3 months, 6 months, 9 months, and 12 months.


• Subgroup analysis by doses showed that low-dose vitamin D supplementation (≤2000 IU/d) was associated with a reduced risk of fetal or neonatal mortality, but higher doses (>2000 IU/d) did not reduce this risk.

"Vitamin D supplementation during pregnancy is associated with a reduced risk of SGA and improved infant growth without risk of fetal or neonatal mortality or congenital abnormality. Vitamin D supplementation with doses of 2000 IU/d or lower during pregnancy may reduce the risk of fetal or neonatal mortality," concluded the authors.

For more information click on the link: 10.1001/jamapediatrics.2018.0302