Lack of a relation between serum 25-hydroxyvitamin D concentrations and asthma in adolescents.

Background: Decreased 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with an increased prevalence and severity of asthma and a lower response to inhaled corticosteroids.

Objective: The objective was to determine the association between serum 25(OH)D concentrations and asthma prevalence, severity, and response to asthma treatment.

Design: Secondary analyses were conducted in 2 samples of adolescents 12-20 y of age: 1) NHANES 2001-2006 (n = 6487), a cross-sectional nationally representative sample of the US population, and 2) a cohort of inner-city adolescents with asthma managed prospectively for 46 wk with guidelines-based therapy in the Asthma Control Evaluation (ACE; n = 226) trial.