According to the results of a systematic review and meta-analysis relatively low dietary intakes of vitamins A and C are associated with statistically significant increased odds of asthma and wheeze. The reviewers searched for studies of asthma, wheeze, or airway responsiveness in association with dietary intakes and serum concentrations of vitamins A, C, and E. Random-effects models allowed estimates of pooled odds ratios (ORs) or mean differences with 95% confidence intervals (CIs). The review included 40 studies meeting the above criteria. Compared with people without asthma, those with asthma had significantly lower dietary vitamin A intake (mean difference, –182 µg/day; 95% CI, –288 to –75 µg/day; 3 studies). In addition, people with severe asthma had significantly lower dietary vitamin A intake vs those with mild asthma (mean difference, –344 µg/day; 2 studies). The odds of asthma were also increased in patients with lower quantile dietary intakes (OR, 1.12; 95% CI, 1.04 - 1.21; 9 studies) and in those with lower serum levels of vitamin C. Although vitamin E intake was generally not associated with asthma status, it was significantly lower in patients with severe asthma vs those with mild asthma (mean difference, –1.20 µg/day; 95% CI, –2.3 to –0.1 µg/day; 2 studies). Limitations of this study include methods used to determine levels of the antioxidant vitamins not consistent across studies, levels of antioxidant vitamins assessed after the onset of asthma in most studies, and most of the studies not reporting adjusted results.