Vitamin C in pregnancy ups child's asthma risk?

While women who take vitamin E during pregnancy seem to lower their offspring's risk of asthma in early childhood, intake of vitamin C may actually raise the risk, according to a recent study by Scottish researchers.

Several reports have linked vitamin E with an apparent protective effect. By contrast, the vitamin C finding is novel and runs counter to previous reports that suggest, at the very least, no effect and possibly a reduced risk of asthma, the investigators report in the American Journal of Respiratory and Critical Care Medicine.

Dr. Sheelagh Martindale and colleagues, from the University of Aberdeen, stand by their findings and the research methods, but acknowledge that confirmatory studies are needed before any recommendations can be made to pregnant women.

The researchers surveyed nearly 2000 healthy women to determine the impact of vitamin intake during pregnancy on the risk of asthma and eczema in the first two years of life.

Neither vitamin C nor vitamin E was associated with the risk of asthma or eczema at 1 year of age, the researchers point out.

As noted, the risk of wheezing at 2 years of age fell as vitamin E intake during pregnancy rose. Moreover, among mothers with allergies, such intake was linked to a reduced risk of eczema for their infants.

In contrast, wheezing and eczema risks at age 2 climbed as vitamin C intake during pregnancy increased. For example, the highest level of intake tripled the risk of wheezing compared with the lowest level.

"Further follow-up of these children will be used to assess whether the associations reported here persist into later childhood and to explore the possibility that any associations may be modified by childhood diet," the investigators state.

SOURCE: American Journal of Respiratory and Critical Care Medicine, January 15, 2005.