Taking folic acid during pregnancy doesn't seem to raise the baby's risk of getting asthma, according to a Dutch study that eases earlier concerns.
In 2009, two research teams reported that folic acid, a B vitamin recommended during pregnancy, might be linked to allergic diseases like asthma or wheezing in the kid.
But expecting moms can breathe easy. According to Dr. Monique Mommers of Maastricht University, the new study did not find "any meaningful association between folic acid supplement use during pregnancy and (allergic diseases) in the offspring."
Getting enough folic acid around the time of conception helps lower the risk of certain birth defects, including spina bifida, a paralyzing malformation of the spine.
Experts advise women to take 400 micrograms of folic acid per day shortly before conceiving and in the first trimester of pregnancy, a critical window of time when neural tube defects take shape.
The Dutch researchers tracked folic acid use among more than 2,600 pregnant women and followed the health of their children for seven years.
Then they tested the kids' lung function and recorded how many developed diseases caused by allergic reactions, including asthma and eczema.
Overall, nearly seven percent of the children developed asthma, regardless of whether their mothers had taken folic acid or not.
The kids' lung function was also similar in the two groups, as was the number of allergic reactions.
According to allergy specialist Dr. Rachel Miller of Columbia University Medical Center, the results "do not suggest any changes in current practices."
Still, Dr. Tsunenobu Tamura, a nutrition expert at the University of Alabama at Birmingham, cautioned that the findings don't prove that folic acid has no side effects. For instance, it's important to monitor long-term outcomes like cancer, he said.
"This type of study should have been done even before the folic acid fortification program was initiated in the United States," he told Reuters Health.