The frequency of vitamin D deficiency among asthmatic Egyptian children

Background: Vitamin D plays a role in the pathogenesis of asthma as it has a potent immunomodulatory effect acting on the cells of the innate immunity. It also reduces the risk of respiratory viral infections which are important initiators of asthma exacerbations. Besides, it potentiates the antiinflammatory action of corticosteroids which are considered the most effective controllers of asthma. Objective: To detect the frequency of vitamin D insufficiency and deficiency among Egyptian asthmatic children and to correlate vitamin D levels to the severity of asthma. Methods: This case control study was conducted on 60 asthmatic children and 40 healthy controls. All were subjected to clinical history taking including history of sun exposure and asthma medications and full clinical examination. Laboratory investigations included measurement of serum calcium, serum alkaline phosphatase and serum 25-OH-D levels and lung functions (spirometery). Results: There was a significant correlation between vitamin D deficiency and severity of asthma, yet there was no significant relation between sun exposure and 25-OH-D level. Moreover, there was a significant relation between decreased serum 25-OH-D levels and the intensity of corticosteroid use. Vitamin D was also significantly lower in asthmatic patients with coexistent allergic rhinitis. Conclusion: Vitamin D deficiency is prevalent in Egyptian children with asthma. Lower levels of serum vitamin D are associated with high asthma severity, reduced asthma control and increased corticosteroid use.