Women who have low levels of vitamin D in their blood during pregnancy increase their odds of having a child with language problems.
A new study from Australia suggests that white women who had the lowest stores of vitamin D during their second trimester were nearly twice as likely to have a child with language difficulties than women with the highest blood concentrations.
Having good stores of vitamin D, the so-called "sunshine vitamin," in the blood while pregnant -- especially during the second and third trimesters -- is needed since this is when certain parts of the fetal brain involved in language-learning develop.
This is also a critical time for the creation of brain pathways and structures that play a role in a child's emotional and behavioral development.
It's been shown that many pregnant women do not have enough vitamin D in their blood. People can get the vitamin from food, such as salmon, milk, eggs, beef liver, and cheese, or the skin can produce it from sunlight.
But many people don't get enough vitamin D in their diets. And the sun may be a less reliable source for women who limit sun exposure and use sunscreen.
The study, which is published online in the journal Pediatrics, looked at 743 pregnant white women in Western Australia. Their blood levels of vitamin D were measured at their 18th week of pregnancy.
Then researchers tracked their children to see if any emotional, behavioral, or language problems turned up. Parents completed a child behavior checklist at ages 2, 5, 8, 10, 14, and 17, and children's language skills were measured at ages 5 and 10 with a picture vocabulary test.
Women with the lowest amounts of vitamin D in their blood during their second trimester of pregnancy had nearly a twofold increase in risk of having a child with language difficulties compared to women with the highest levels of the vitamin.
These findings held true even when researchers took into account other factors that could have influenced the results, such as the mother's age during pregnancy and whether she smoked, as well as family income.
The study did not find that a mother's vitamin D levels were connected to her child's emotional and behavioral development.
Scientists suspect that reduced levels of vitamin D in the mother during this critical time in the brain's development appear to be linked with language learning problems when a child reaches school age.
Researchers conclude that "maternal vitamin D supplementation during pregnancy may reduce the risk of developmental language difficulties among their children."