Women who took folic acid supplements in the first two months of pregnancy were less likely to have kids with severe language delays, according to a new study from Norway.
"We don't think people should change their behaviour based on these findings," said Dr Ezra Susser from Columbia University's Mailman School of Public Health in New York, who worked on the study. "But it does add weight to the public health recommendation to take folic acid early in pregnancy."
The researchers gave surveys to close to 40,000 Norwegian women a few months into their pregnancies, including questions on what supplements women were taking in the four weeks before they got pregnant through eight weeks after conception.
Then, when their children were three years old, Dr Susser and his colleagues asked the same women about kids' language skills, including how many words they could string together in a phrase.
Toddlers who could only say one word at a time or who had "unintelligible utterances" were considered to have severe language delay. In total, about one in 200 kids fit into that category.
Children born to women who took folic acid
Four out of 1,000 children born to women who took folic acid alone or combined with other vitamins had severe language delays, compared to nine of 1,000 kids whose moms didn't take folic acid before and early in pregnancy.
The link persisted after Dr Susser's team adjusted for other factors that were associated with both folic acid supplementation and language skills, such as maternal weight, education, and marital status.
The study can't prove that folic acid, itself, prevents language delay, the authors wrote today in the Journal of the American Medical Association. But Dr Susser said the vitamin is known to affect the growth of neurons and could influence how proteins are made from certain genes.
"Clearly it plays a role in development that starts very early in pregnancy," said Usha Ramakrishnan, a maternal and child nutrition researcher from Emory University in Atlanta who wasn't involved in the new study.
However, she added, it's hard to separate out exactly when during pregnancy folic acid supplements would have an effect on later language development – since women who are taking supplements early are more likely to take them throughout pregnancy.
Grains fortified with folic acid
Dr Susser said the results likely apply in the US and other countries where grains are fortified with folic acid, because extra supplements are still recommended during pregnancy. But he added that more research is needed to support the new study.
"The recommendation worldwide is that women should be on folate supplements through all their reproductive years," Dr Susser said. Because of that, "we really need to know what the impact is on children, both benefits and risks."
"I think this adds to what's already known about the benefits of folic acid," Ramakrishnan said. "It gives one more positive message of potential benefit."
(Reuters Health, Genevra Pittman, October 2011)