HealthDay News — Among children at risk for asthma, prenatal vitamin D supplementation does not affect the incidence of asthma or recurrent wheeze at age 6, according to a study published in the Feb. 6 issue of the New England Journal of Medicine.
Augusto A. Litonjua, MD, MPH, from the University of Rochester Medical Center in New York, and colleagues followed children enrolled in a trial of prenatal vitamin D supplementation to prevent asthma and recurrent wheeze in young children from age 3 to 6 years. The impact of maternal vitamin D supplementation during pregnancy (mothers received either 4400 IU [vitamin D group] or 400 IU [control group] of vitamin D3 per day) was examined on the incidence of asthma and recurrent wheeze at age 6 years.
The researchers found that in neither the intention-to-treat analysis nor an analysis with stratification according to the maternal 25-hydroxyvitamin D level during pregnancy was there an effect of maternal vitamin D supplementation on asthma and recurrent wheeze. Vitamin D supplementation also had no effect on most of the prespecified secondary outcomes. A very small effect on airway resistance was seen, as measured by impulse oscillometry, although the significance of this finding was uncertain.
“The effect of prenatal supplementation on airway resistance through the age of 6 years suggests that there may be prenatal programming of lung airways, but these small effects will need to be validated in future studies,” the authors write.