High prevalence of vitamin D deficiency among inner-city African American youth with asthma in Washington, DC.

Objective: The goal of this study was to examine the prevalence of vitamin D insufficiency and deficiency among urban African-American (AA) youth with asthma compared with control subjects without asthma.

Study Design: A cross-sectional case-control study was conducted at an urban pediatric medical center. Total 25-hydroxyvitamin D insufficiency (<30 ng/mL) and deficiency (<20 ng/mL) were assessed in urban self-reported AA patients, aged 6 to 20 years, with (n = 92) and without (n = 21) physician-diagnosed asthma.

Results: Blood samples were available for 85 (92%) cases. The prevalence of vitamin D insufficiency and deficiency were significantly greater among cases than control subjects (73/85 [86%] vs 4/21 [19%], adjusted odds ratio = 42 [95% confidence interval: 4.4 to 399] for insufficiency and 46/85 [54%] vs 1/21 [5%], adjusted odds ratio = 20 [95% confidence interval: 1.4 to 272] for deficiency).

Conclusions: Most of this sample of urban AA youth with persistent asthma were vitamin D deficient or insufficient. Given the emerging associations between low vitamin D levels and asthma, strong consideration should be given to routine vitamin D testing in urban AA youth, particularly those with asthma.