title: Supplementation with vitamin A early in life and subsequent risk of asthma.
abstract: Animal models suggest that vitamin A deficiency affects lung development adversely and promotes airway hyperresponsiveness, and may predispose to an increased risk of asthma. We examined the long-term effects of vitamin A supplementation early in life on later asthma risk. In 2006-2008, we revisited participants from two cohorts in rural Nepal who were enrolled in randomised trials of vitamin A supplementation. The first cohort received vitamin A or placebo for <16 months during their pre-school years (1989-1991). The second cohort was born to mothers who received vitamin A, β-carotene or placebo before, during and after pregnancy (1994-1997). At follow-up, we asked about asthma symptoms and performed spirometry. Out of 6,421 subjects eligible to participate, 5,430 (85%) responded to our respiratory survey. Wheezing prevalence during the previous year was 4.8% in participants aged 9-13 yrs and 6.6% in participants aged 14-23 yrs. We found no differences between the vitamin A supplemented and placebo groups from either trial in the prevalence of lifetime or current asthma and wheeze or in spirometric indices of obstruction (p ≥ 0.12 for all comparisons). Vitamin A supplementation early in life was not associated with a decreased risk of asthma in an area with chronic vitamin A deficiency.
authors.affiliation: Critical Care Dept of Medicine, Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University, Baltimore, MD 21212, USA. wcheckl@jhmi.edu
authors.forename: W
authors.initials: W
authors.lastname: Checkley
authors.forename: K P
authors.initials: KP
authors.lastname: West
authors.forename: R A
authors.initials: RA
authors.lastname: Wise
authors.forename: L
authors.initials: L
authors.lastname: Wu
authors.forename: S C
authors.initials: SC
authors.lastname: LeClerq
authors.forename: S
authors.initials: S
authors.lastname: Khatry
authors.forename: J
authors.initials: J
authors.lastname: Katz
authors.forename: P
authors.initials: P
authors.lastname: Christian
authors.forename: J M
authors.initials: JM
authors.lastname: Tielsch
authors.forename: A
authors.initials: A
authors.lastname: Sommer
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D019587:Dietary Supplements; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009390:Nepal / Q000453:epidemiology; D015995:Prevalence; D016032:Randomized Controlled Trials as Topic; D012135:Respiratory Sounds / Q000175:diagnosis; D012306:Risk; D013147:Spirometry; D014801:Vitamin A / Q000008:administration & dosage*; D014815:Vitamins / Q000008:administration & dosage*; D055815:Young Adult; D019207:beta Carotene / Q000008:administration & dosage
chemical_list: D014815:Vitamins; D019207:beta Carotene; D014801:Vitamin A