The authors investigated the relation between children's pulmonary function and intake of fruits, vegetables, juices, and vitamins A, C, and E by examining cross-sectional data from 2,566 children in the Children's Health Study collected during 1997-1998. Low total vitamin C intake (< or =10th percentile) was associated with deficits in forced vital capacity for both boys and girls and with deficits in flows that were larger in girls (forced expiratory volume in 1 second (FEV1), -3.3%, 95% confidence interval (CI): -6.0, -0.5; forced expiratory flow between 25% and 75% of forced vital capacity (FEF(25-75)), -5.5%, 95% CI: -10.5, -0.3) compared with boys (FEV1, -2.3%, 95% CI: -4.8, 0.3; FEF(25-75), -2.4%, 95% CI: -7.4, 2.8). Low dietary vitamin E intake was associated with lower FEF(25-75) (boys: FEF(25-75), -8.9%, 95% CI: -14.2, -3.3; girls: FEF(25-75), -2.5%, 95% CI: -8.3, 3.7). Deficits in FEF(25-75) were associated with low dietary vitamin A intake in girls (FEF(25-75), -7.9%, 95% CI: -12.7, -2.8) and with low total vitamin A intake in boys with asthma (FEF(25-75), -15.6%, 95% CI: -27.6, -1.6). Low intakes of orange and other fruit juices, which were the largest source of vitamin C, were associated with deficits in forced vital capacity and FEV1 in boys. In summary, lung function levels were lower in children with inadequate dietary antioxidant vitamin intake.