Serum vitamin D levels and exercise-induced bronchoconstriction in children with asthma

Abstract

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 (DFEV1) 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 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.

Effect of Vitamin D and Inhaled Corticosteroid Treatment on Lung Function in Children

“…Multiple previous studies have found that inhaled corticosteroids improve lung function (16). Our finding that children who are vitamin D deficient are more likely to have lower lung function is consistent with a previous study that demonstrated that in children with exerciseinduced bronchoconstriction, lower vitamin D levels were associated with reduced lung function (17). Our study's result that children with asthma who are vitamin D sufficient have improved lung function is also supported by other studies.…”

Effects of Vitamin D Levels on Asthma Control and Severity in Children

“…Alyasin ve ark.nın (31) çalışmasında D vitamini düzeylerinde düşüklük ile astım şiddeti ve hastaneye yatma oranları arasında bizim çalışma sonuçlarımızın aksine bir ilişki saptanmadı. Bu sonuç da onların çalışma grubunun yaş aralığının (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) …”

“…Bazı kesitsel çalışmalarda serum D vitamini düzeylerinin astımlı çocuklarda sağlıklı çocuklara göre daha düşük olduğu (4,(10)(11)(12) sınırlı sayıdaki çalışmada serum D vitamini düzeylerindeki yüksekliğinin astım riskinde artmaya neden olduğu gösterilmiştir (13,14). Bazı çalışmalarda ise bu farklılıklar gözlenmemiştir (15)(16)(17)(18)(19). D vitamini ve günümüzdeki astım rehberlerinde astım tedavisinin ana amacı olarak ifade edilen astım kontrolü ilişkili yapılmış sınırlı sayıda çalışma vardır.…”

Bronchial Reactivity, Inflammatory and Allergic Parameters, and Vitamin D Levels in Children With Asthma

“…15 Other studies have shown that low serum vitamin D levels are associated with reduced lung function in adolescents, 16 poor asthma control, 17 and the presence of exercise-induced bronchoconstriction in children with asthma. 18 A recent study showed increased levels of vitamin D-binding protein and 25-hydroxyvitamin D in bronchoalveolar lavage fluid after allergen challenge, suggesting a role for these factors in allergic late-phase reactions. 19 A low serum vitamin D level may represent a marker of Western life style.…”