Effect of prenatal supplementation with vitamin D on asthma or recurrent wheezing in offspring by age 3 years

Lack of vitamin D during pregnancy can lead to breathing disorders early in a child’s life. Researchers tested whether prenatal vitamin D supplementation could prevent asthma or recurrent wheezing by administering specific doses to 876 women aged 18–39 years. One group received vitamin D 4,000 IU plus a prenatal vitamin containing vitamin D 400 IU, while the second group received a placebo plus a prenatal vitamin containing vitamin D 400 IU. A total of 806 infants were analyzed.