To investigate, the asthma-related outcomes of more than 1,000 children in the previous study were assessed when they reached 5 years of age.
Mother's nutrient status was assessed through food frequency questionnaires and blood tests, and the presence of asthma in children was evaluated using respiratory questionnaires, imaging and skin-prick tests.
The researchers found the low maternal vitamin E levels were associated with having a child with asthma, persistent wheeze, wheezing or asthma during the previous year, or ever having a diagnosis of asthma, the authors note. An inverse relationship was also seen, with high maternal vitamin E levels being associated with a lower risk of having a child with asthma or related symptoms.
The researchers also found a negative association between maternal zinc levels and children with active asthma or those who had ever been diagnosed with asthma.
The results were the same regardless of the nutrient status of the children.
Based on animal researches, Dr. Graham Devereux, lead author of the study, offered two possibilities for how low maternal vitamin E may raise the risk of childhood asthma. First, that a deficiency of vitamin E in the womb leads to impaired lung development. Second, low vitamin E levels might adversely affect the immune system, resulting in a more asthma-prone environment.
In an interview with Reuters Health, Devereux, however, emphasized that the study does not imply that the pregnant women should start stocking up on Vitamin E, rather they should go for a healthy diet.
