TUESDAY, July 14, 2026 (HealthDay News) -- Higher vitamin A is associated with better lung function in children and adults, while vitamin D levels are associated with lower epigenetic aging in asthma in adults, according to a study published online June 30 in Thorax.Rinku Sharma, Ph.D., from Brigham and Women's Hospital in Boston, and colleagues examined the impact of vitamins A and D on lung function, epigenetic aging and regulatory epigenetics in children and adults with asthma. The analysis included data from two asthma cohorts: Genetic Epidemiology of Asthma in Costa Rica Study (1,165 children) and Omic Determinants of Longitudinal Lung Function in Asthma (1,041 adults).The researchers found that in children, higher levels of vitamin A were associated with higher forced expiratory volume in 1 second (FEV1; β = 2.5) and forced vital capacity (FVC; β = 7.6) but lower FEV1/FVC (β = −3.9), while vitamin D showed no association. In adults, both vitamins were positively associated with FEV1 (vitamin A: β = 4.7; vitamin D: β = 0.16) and FVC (vitamin A: β = 3.4; vitamin D: β = 0.18). Only vitamin A was associated with FEV1/FVC (vitamin A: β = 2.5). In adults, vitamin D sufficiency corresponded to lower epigenetic aging. There was an association between higher vitamin levels and IRF5 regulatory cytosine hypomethylation at cytosine-guanine dinucleotides, corresponding to better lung function and lower aging. There were distinct vitamin-associated miRNAs identified, with shared targets enriched in immune and cell-cycle pathways. There was partial mediation through methylation and miRNAs."Our findings emphasize that epigenetic mechanisms play a key role in mediating the effects of vitamins on lung function in individuals with asthma, pointing to potential targets for personalized nutrition and therapeutic strategies in asthma care," the authors write.Abstract/Full Text.Sign up for our weekly HealthDay newsletter