Supplement may put baby at risk for asthma

January 6, 2010 A new study finds that children whose mothers took folic acid from the 30th week on were one-quarter more likely to have asthma at age 3.

Researchers reporting in the American Journal of Epidemiology emphasize that this does not implicate folic acid use in early pregnancy.

The supplement has been shown to help protect against birth defect when taken in the first trimester. Why it could cause problems later is unclear, but some research suggests could alter the activity of immune regulating genes in the lung tissue.