High Prevalence of Vitamin D Deficiency among Inner-City African American Youth with Asthma in Washington, DC

Abstract

Objective Low vitamin D levels have been implicated in the development of and increased morbidity from asthma. The prevalence of asthma among urban African American (AA) youth is high. The goal of this study was to examine the prevalence of vitamin D insufficiency and deficiency among urban AA youth with asthma compared with non-asthmatic controls. 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. After adjusting for age, gender, body mass index percentile, and season of sampling, the median vitamin D level of cases [18.5 (interquartile range (IQR): 11.3, 25.1)] was significantly lower than that of controls [40.4 (IQR: 34.6, 49.5), P = 0.002]. The prevalences of vitamin D insufficiency and deficiency were significantly greater among cases than controls [73/85 (86%) vs. 4/21 (19%), adjusted odds ratio (OR) = 41.7 (95% confidence interval (95%CI): 4.4 to 398.5) for insufficiency and 46/85 (54%) vs. 1/21 (5%), adjusted OR = 19.5 (95%CI: 1.4 to 272.0) for deficiency]. Conclusions A majority of this sample of urban AA youth with persistent asthma were vitamin D deficient and/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. Clinical trials of vitamin D supplementation among urban AA youth with asthma are warranted.

Vitamin D Levels of Asthmatic Children with and Without Obesity

“…claimed no relationship between asthma and vitamin D levels (8,14,15,18). As a matter of fact this was the case in our study as vitamin D deficiency was present in 97.5% and insufficiency was present in 2.5% of our study group and Vitamin D levels did not differ between patients with and without asthma.…”

“…In a study, the frequency of vitamin D deficiency (54%) or insufficiency (86%) in 92 African-American asthmatic children aged 6-20 years was found to be higher than in healthy controls (18). However, there are other studies that did not find a difference in Vitamin D levels between patients with and without asthma (8,(13)(14)(15).…”

“…Low Vitamin D levels have been shown to be associated with a high body mass index (BMI) in some studies (16)(17)(18) although there are reports that did not reveal a relationship (19). Vitamin D is thought to affect BMI by stimulation of lipogenesis and suppression of lipolysis (20).…”

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

“…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).…”

Effect of Vitamin D Supplementation on Moderate to Severe Bronchial Asthma: Correspondence 1

“…Change in level of severity of asthma as per the GINA guidelines is the primary outcome measure for this study. The expected change in the severity of asthma should have been first ascertained in the light of various previous studies on the association of vitamin D deficiency in asthmatic children [2][3][4][5]. Subsequent calculation of sample size based on this value of change in asthma severity with vitamin D could have resulted in better understanding of the effect size of vitamin D supplementation.…”