Background:
Asthma is a common childhood disorder with complex pathobiologic components that may include aspects of nutritional deficit. The contribution of
vitamin deficiency, specifically
vitamin A, as part of the disease complex has not been well studied, particularly among at risk children. In this study, we examined the prevalence of
vitamin A as well as
zinc deficiency in conjunction with visual function among an urban pediatric population sample with moderate-severe persistent
asthma. Methods: A cross-sectional case-control assessment of serum
vitamin A,
zinc and visual function among urban children with and without
asthma was undertaken. Inclusion criteria involved (1) well-controlled pediatric asthmatic patients between the ages of 8-18 with corrected vision of at least 20/25 in each eye and (2) chronic use of a combination beta agonist-
steroid inhaler. Visual function was assessed by Snellen visual acuity and Peli Robson contrast sensitivity assessment. Results: Overall, 24 patients were enrolled for study with body mass index and age matched between asthmatic and control groups. Median serum
vitamin A and
zinc levels among control subjects was statistically higher compared to asthmatics (p = 0.0303 and p = 0.0111, respectively). Based on age-based reference levels there was no evidence of
vitamin A or
zinc deficiency among asthmatics or controls. Serum
vitamin A and
zinc were found to directly correlate with body mass index (p = 0.0074 and p = 0.0474, respectively), but not age or measures of visual function. Contrast sensitivity was however significantly reduced among asthmatic subjects (p = 0.0003). Conclusions: Children with chronic
asthma demonstrate reduced levels of
vitamin A and
zinc that may be related to disease pathobiology however, evidence of frank
zinc or
vitamin A deficiency was not demonstrated. Reduced contrast sensitivity found in the asthmatic group appears unrelated to serum
vitamin A and/or
zinc levels.