Mothers who had low vitamin D levels while they were pregnant are more likely to have a child with a language impairment than moms who had higher levels of the vitamin, according to a new study from Australia.
Vitamin D is important for fetal development, but "the effects of lower maternal vitamin D levels on the developing offspring is not fully understood," said Andrew Whitehouse, the lead author of the study.
Whitehouse said earlier studies have shown some links between low vitamin D during pregnancy and problems in children such as weaker bones, asthma and poor growth.
He and his colleagues, based at the University of Western Australia, sought to determine whether vitamin D levels in the moms might have anything to do with kids' later behavioral and language development as well.
Twenty years ago, they measured the vitamin D levels of more than 700 women who were about half-way through their pregnancy.
Five and 10 years later, they tested the children of these moms to measure their behavioral and emotional development and language skills.
The researchers split the moms into four groups -- from lowest to highest vitamin D levels -- and they found that the risk of having a kid with emotional or behavioral issues was the same for each group.
The low-vitamin D group had between 15 and 46 nanomoles per liter (nmol/L) in their blood, while the high-vitamin D group had 72 to 154 nmol/L. Levels below 30 nmol/L are considered deficient.
When the researchers looked at language skills, the team found that mothers in the lowest category were more likely to have a child with a language impairment than mothers in the highest vitamin D category.
The language impairments were determined from scores on a vocabulary test.