Vitamin D and Asthma Symptoms in a Cohort of Inner-City Children in Baltimore, MD

Abstract

ISEE-0872 Background and Objectives: Low vitamin D levels have been associated with a variety of health problems including increased risk for cancer, respiratory infections, atopy, and possibly asthma severity. The purpose of this paper is to examine the relationship between Serum vitamin D and symptoms in asthmatic children living in Baltimore, MD. Methods: A cohort of 124 asthmatic children living in inner city Baltimore, MD had asthma symptoms and serum 25-hydroxyvitamin D assessed at baseline. Symptoms were also assessed at 3 months and 6 months. Longitudinal data analysis (GEE) was used to estimate the impact of vitamin D on asthma symptoms. Results: Study participants were 2–6 years of age, predominantly African American (>90%) and from households of low economic status. Median serum vitamin D in this cohort was 29 ng/ml, with a range of 7 to 53 ng/ml. Fifty-five percent had serum levels less than normal (30 ng/ml), including a 23% with vitamin D deficiency (< 20 ng/ml). Vitamin D levels were associated with symptoms of asthma, especially cough in the last two weeks. For every 1 ng/ml increase in vitamin D level there was a 2% reduction in the number of days of symptoms over the past 2 weeks (P < 0.05). There was also a 1% increase in symptoms while running in the last two weeks for every 1 ng/ml increase in vitamin D that did not reach statistical significance (P < 0.17). Conclusion: Lower vitamin D levels are associated with increased cough among childhood asthmatics in a cohort of inner-city Baltimore pre-school aged children. Intervention studies are needed to determine if vitamin D supplementation can ameliorate symptoms of asthma in children.