Vitamin D Supplementation During Pregnancy and the Prevention of Childhood Asthma

Abstract

(N Engl J Med. 2020;382:574–575) Asthma symptoms often first appear when children are preschool-age, and therefore many efforts to prevent asthma are aimed at the prenatal or early postnatal periods. During the preschool years, asthma symptoms and transient wheeze are nearly identical, so the outcomes of any intervention should be measured once children reach 5 or 6 years old.