title: Are children with asthma in South Korea also associated with vitamin D deficiency?
abstract: Recently, epidemiologic studies have shown that the lack of serum vitamin D levels may be associated with high asthma prevalence, but its effect is still controversial, depending on season, area, and food consumption. We aimed to examine the association of serum vitamin D levels with the prevalence of pediatric asthma in Korea. A total of 80 children (50 asthmatic children and 30 healthy controls) aged 6-14 years were participated in this study. Serum vitamin D levels were measured and compared between the two groups. Moreover, the relationship of serum vitamin D levels with results of pulmonary function test and environmental factors (lifestyle habits and residential factors) collected by a questionnaire survey were examined in asthmatic patients. Serum vitamin D levels in asthmatic children (16.63±4.20 ng/mL) were significantly lower than that in healthy controls (24.24±6.76 ng/mL) (p<0.05). Also, we found that the prevalence of asthma increase to 0.79-fold (odds ratio, 0.79; 95% confidence interval, 0.71 to 0.88;p<0.001) as serum vitamin D level is 1 ng/mL decreases. The increased time spent in outdoor could affect the increases of serum vitamin D levels significantly. However, no associations of serum vitamin D with pulmonary function and residential environmental factors (i.e., housing type, living floor, and indoor activity time) were observed. Our findings suggest that serum vitamin D levels were also associated with pediatric asthma in Korea. Moreover, management of serum vitamin D level in asthmatic children would be a promising approach for preventing exaggeration of their severity.
authors.affiliation: Environmental Health Center for Asthma, Korea University Medical Center, Seoul, Korea.
authors.forename: Yu-Ri
authors.identifier: 0000-0003-1286-4271
authors.initials: YR
authors.lastname: Kim
authors.affiliation: Department of Industrial Health, College of Applied Sciences, Catholic University of Pusan, Busan, Korea.
authors.forename: Sung Chul
authors.identifier: 0000-0001-8301-6355
authors.initials: SC
authors.lastname: Seo
authors.affiliation: Environmental Health Center for Asthma, Korea University Medical Center, Seoul, Korea.|Department of Pediatrics, Korea University College of Medicine, Seoul, Korea.
authors.forename: Young
authors.identifier: 0000-0003-3354-6969
authors.initials: Y
authors.lastname: Yoo
authors.affiliation: Environmental Health Center for Asthma, Korea University Medical Center, Seoul, Korea.|Department of Pediatrics, Korea University College of Medicine, Seoul, Korea.
authors.forename: Ji Tae
authors.identifier: 0000-0003-0432-4048
authors.initials: JT
authors.lastname: Choung
keywords: Asthma; Child; Pulmonary function test; Serum; Sunlight; Vitamin D