Low levels of vitamin D during pregnancy are
associated with an increased risk of complications in mothers-to-be and low
birth weight in their newborns, a new study finds.
The research shows an association but doesn't
prove that insufficient vitamin D causes complications. Still, taking vitamin D
supplements may help reduce these risks, the researchers
Researchers examined data from 31 studies
published between 1980 and 2012. The studies had between 95 and 1 100
The analysis revealed that pregnant women with
low levels of vitamin D were more likely to develop gestational diabetes
(diabetes during pregnancy) and preeclampsia (high blood pressure and protein in
the urine). They were also more likely to have a low birth weight
The findings are "concerning" given recent evidence that low levels of vitamin
D are common during pregnancy, particularly among vegetarians, women with
limited sun exposure and those with darker skin, the researchers
The body makes vitamin D when the skin is exposed
to sunlight. Other sources include supplements and certain types of foods, such
as fish. Milk is usually fortified with vitamin D.
While the study identified a significant
association between low vitamin D levels and an increased risk for pregnancy
complications, further research is need to determine whether programmes to boost
vitamin D levels in pregnant women would reduce those risks, the researchers at
the University of Calgary in Canada wrote.
The findings support a goal of ensuring that all
pregnant women have adequate levels of vitamin D, according to an accompanying
editorial by Robyn Lucas, of the National Center for Epidemiology and Population
Health at the Australian National University in Canberra.
She said that vitamin D "supplements, diet and
sunlight exposure" are all measures that "should be used together, with care."
Large, well-controlled studies are still needed to clarify the association
between too little vitamin D in pregnancy and birth complications, she said in a
journal news release.
The Harvard School of Public Health has more
D and health