Babies born to women who took folic acid supplements before and during pregnancy are at a lower risk for difficulties in developing their language skills, a new study says.
Taking folic acid for a period starting four weeks before conception through eight weeks after conception more than halved a child's risk of developing a severe language delay at age 3. Three year olds who spoke in one-word utterances, or who were intelligible, were considered to have a severe language delay, the study said.
The study included 39,000 children in Norway, 204 of whom had a severe language delay. Of the 9,000 children whose mothers took no folic acid, 0.9 percent developed a severe language delay. But among the 26,0000 children whose mothers took folic acid, 0.4 percent developed severe language delays.
Studies have shown that taking folic acid before pregnancy reduces the risk of neural tube defects, but none had previously looked at how the vitamin affects the signs of neurodevelopment that show up after birth, the study said.
Unlike the U.S., Norway does not fortify foods with folic acid, so there is a larger contrast in folate levels between women taking supplement and those not taking it, the study said.
Taking folic acid had no effect on gross motor skills , the researchers found.
The study shows only an association, but if a causal link was proven, it would have important implications for researchers' understanding of the process of neurodevelopment, the study said.
The study is published today (Oct. 12) in the Journal of the American Medical Association.