University of Calgary

Low intake of vitamin D harms newborns, pregnant moms, study finds

UToday HomeMarch 27, 2013

Fariba Aghajafari, a family physician and member of the University of Calgary’s Institute for Public Health, is the study’s first author.Fariba Aghajafari, a family physician and member of the University of Calgary’s Institute for Public Health, is the study’s first author.A new study from the University of Calgary’s Faculty of Medicine has shown there is a significant link between vitamin D insufficiency and adverse health outcomes in mothers-to-be and newborns. The study is published in the British Medical Journal today.

Researchers carried out a systematic review and meta-analysis of all existing evidence on the effect of vitamin D concentration on pregnancy and birth outcomes. Observational data has suggested a link between low vitamin D and increased risk of adverse pregnancy outcomes such as gestational diabetes, preeclampsia, risk of infections, caesarean section, and fetal growth restriction such as low birth weight. Knowledge of these associations is however limited.

Data from 31 studies, published between 1980 and 2012 and involving anywhere from 95 to 1,100 participants, was included in the analysis. Differences in study design and quality were taken into account to minimize bias.

Results showed that pregnant women with insufficient vitamin D were at a 49-per-cent increased chance of developing gestational diabetes, a 79-per-cent increased chance of developing preeclampsia, a 187-per-cent increased chance of developing bacterial vaginosis and an 85-per-cent increased chance of giving birth to a baby small for gestational age. No significant differences were found in birth length and head circumference.

“These results are concerning, given recent evidence that vitamin D insufficiency is common during pregnancy, especially among high risk women, vegetarians, women with limited sun exposure and ethnic minorities with darker skin,” says the study’s first author, Dr. Fariba Aghajafari, a family physician and member of the University of Calgary’s Institute for Public Health.

“Fortunately, optimizing vitamin D intake in expectant mothers may be a simple way to reduce the risk of these adverse outcomes.”

While the findings identify a significant association, researchers stress the need for further studies to be done.

“There remains a need for large, well-designed randomized controlled trials to determine whether strategies to optimize vitamin D concentration are effective in improving pregnancy and neonatal outcomes,” says the study’s lead author, Dr. Doreen Rabi, an endocrinologist and member of the University of Calgary’s Institute for Public Health and the Libin Cardiovascular Institute of Alberta. “Future studies should look at the dose-response relationship between vitamin D supplements and adverse health outcomes.”

Dr. Doreen Rabi is supported by Alberta Innovates – Health Solutions.

 

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