Serum vitamin D levels and exercise-induced bronchoconstriction in children with asthma.
Epidemiological studies have established a relationship between low levels of serum vitamin D and reduced lung function in healthy adults, and asthma onset and severity in children. However, no study has examined the relationship between vitamin D levels and exercise-induced bronchoconstriction in asthmatic children. We evaluated the relationship between 25-hydroxyvitamin D concentrations and baseline forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and change in FEV1 (ΔFEV1) after a standardised exercise challenge in 45 children with intermittent asthma. Only 11% of the children had desirable serum vitamin D levels (at least 30-40 ng·mL(-1)). A positive correlation was found between serum 25-hydroxyvitamin D and both FVC (r=0.34; p=0.037) and FEV1 (r=0.32; p=0.037). Subjects with a positive response to the exercise challenge (ΔFEV1≥10%) presented lower serum levels of 25-hydroxyvitamin D than children with a negative challenge (mean±sd 16.2±5.2 versus 23.4±7.0 ng·mL(-1), respectively; p=0.001). Our results indicate that hypovitaminosis D is frequent in asthmatic children who live in a Mediterranean country. In those children, lower levels of vitamin D are associated with reduced lung function and increased reactivity to exercise.
Department of Paediatrics, University of Verona, Policlinico GB Rossi, Piazzale L. Scuro, 37134 Verona, Italy.
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Chinellato
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Piazza
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Sandri
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Peroni
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Cardinale
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Boner
D001250:Asthma, Exercise-Induced / Q000097:blood* / Q000503:physiopathology; D016084:Bronchoconstriction / Q000502:physiology; D002648:Child; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D014797:Vital Capacity / Q000502:physiology; D014807:Vitamin D / Q000097:blood* / Q000502:physiology
D014807:Vitamin D