A study of vitamin intake in pregnant women found an increased risk of infants developing wheezing problems as toddlers. The study, reported in the American Journal of Respiratory and Critical Care Medicine (January 14, 2005), found that a low dietary intake of vitamin E during pregnancy is connected with a higher risk of wheezing at age 2.

For the study, the researchers analyzed data from 1300 mothers and their children. The mothers answered a 145-item food frequency questionnaire that focused on their diet during pregnancy. The results of the study indicated that a higher vitamin E intake during pregnancy was linked with fewer incidences of wheeze in the absence of a cold. The researchers were surprised, however, when they looked at the vitamin C intake. While it showed an increased wheeze at age 2, researcher Graham Devereux, MD, PhD, said, "We strongly suspect that this association is spurious; it contradicts all previous work. We have not demonstrated an association between vitamin C and infant immune responses."

Dr. Graham stressed that the findings are preliminary and warrant further studies. He noted that until more studies are completed women should not change their diet during pregnancy.