Maternal vitamin D and E intakes in pregnancy and asthma to age 15 years: A cohort study.

This study investigated whether the previously reported associations in this birth cohort between maternal vitamin D and E intakes during pregnancy and childhood wheeze/asthma outcomes at age 5 and 10 years are still evident at age 15 years. In a prospective study of 1924 children recruited in utero, maternal vitamin D and E intakes during pregnancy were assessed by food frequency questionnaire and the children completed raespiratory questionnaire at age 15 years. Treatment for asthma at age 15 was also ascertained using healthcare data. Maternal vitamin D and E intakes were also related to combined childhood asthma data collected at 1, 2, 5, 10, and 15 years of age. Symptom data were available for 747 (39%) 15-year olds and healthcare data for 1689 (88%). There were no associations between maternal vitamin D and E intakes and childhood wheeze and asthma at age 15. Analysis of combined data collected between 1 and 15 years of age demonstrated that higher maternal vitamin D and E intakes during pregnancy were associated with a reduced likelihood of being diagnosed with asthma in the first 15 years: hazard ratio (95%CI) per quartile increase in vitamin intake of 0.87 (0.78,0.98) and 0.88 (0.78,0.98), respectively. Lower maternal vitamin D and E intakes during pregnancy are associated with increased risk of children wheezing and being diagnosed with asthma in the first 10 years but not after puberty, suggesting that post-natal exposures predominate in the etiology of incident asthma as children transition through puberty into adulthood.