Vitamin D in Pregnancy Critical for Brain Development, Study Says

Babies whose mothers had adequate levels appeared to do better on mental, motor tests

By Carina Storrs
HealthDay Reporter

MONDAY, Sept. 17 (HealthDay News) -- Vitamin D deficiency during pregnancy could hinder babies' brain development, impeding their mental and motor skills, a new study suggests.

Researchers in Spain measured the level of vitamin D in the blood of almost 2,000 women in their first or second trimester of pregnancy and evaluated the mental and motor abilities of their babies at about 14 months of age. The investigators found that children of vitamin D-deficient mothers scored lower than those whose mothers had adequate levels of the sunshine vitamin.

"These differences in the mental and psychomotor development scores do not likely make any difference at the individual level, but might have an important impact at the population level," said study lead author Dr. Eva Morales, a medical epidemiologist in the Center for Research in Environmental Epidemiology in Barcelona.

Overall, lower scores in these tests could lead to lower IQs among children, Morales added.

The study was published online Sept. 17 and in the October print issue of the journal Pediatrics.

Previous research has linked insufficient levels of vitamin D during pregnancy with language impairment in children at 5 and 10 years of age.

Despite these connections, experts still debate how much vitamin D pregnant women should receive.

The Institute of Medicine, an independent U.S. group that advises the public, recommends pregnant women get 600 international units (IU) a day of vitamin D and no more than 4,000 IU/day. However, the Endocrine Society says that 600 units does not prevent deficiency and that at least 1,500 to 2,000 units a day may be required.

Bruce Hollis, director of pediatric nutritional sciences at the Medical University of South Carolina in Charleston, said the recommended 600 units per day is probably sufficient to promote good skeletal health in fetuses, but it "basically does nothing" to prevent other diseases.

Other studies have reported that low prenatal vitamin D levels could weaken a baby's immune system and increase the risk of asthma and other respiratory conditions, and heart disease.

Hollis recommends that women who are pregnant or want to become pregnant get 4,000 units a day of vitamin D.