Andino D, et al. - Researchers performed this cross-sectional case–control analysis in urban children with moderate–severe persistent asthma, to determine the prevalence of vitamin A as well as zinc deficiency in conjunction with visual function in these individuals. This study also included children without asthma. Pediatric asthmatic patients having a well-controlled disease and aged between 8–18 years with corrected vision of at least 20/25 in each eye and were chronic users of a combination beta agonist-steroid inhaler were eligible for inclusion. Reduced levels of vitamin A and zinc were found in children with chronic asthma, which may be associated with disease pathobiology. However, there was no evidence of frank zinc or vitamin A deficiency. In the asthmatic group, reduced contrast sensitivity was noted, which seemed not associated with serum vitamin A and/or zinc levels.