Higher levels of circulating vitamin A are associated with better lung function in children and adults with asthma, while vitamin D shows similar benefits in adults, including slower biological ageing, according to a study published online in the respiratory journal Thorax on June 30.
Researchers explained that poor lung function is a key predictor of death regardless of whether a person has lung disease. Maintaining healthy lungs is essential for preventing long-term respiratory conditions. Previous research has suggested that vitamins A and D can both protect against and worsen asthma, as well as influence lung development depending on dose and context.
To clarify the role of these vitamins, the study analyzed two groups: 1,165 children from the Genetic Epidemiology of Asthma in Costa Rica Study (GACRS) and 1,041 adults from the Omic Determinants of Longitudinal Lung Function in Asthma (ODOLLFA). Measurements included serum microRNAs (miRNAs), DNA methylation status, vitamin A and D levels, as well as assessments of forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV:FVC ratio.
The findings indicated that both children and adults with higher vitamin A levels had better FEV1 and FVC than those with lower levels. Among adults with asthma, those whose vitamin D levels were at least 30 ng/ml also had better lung function compared to those with lower levels. These individuals showed less evidence of epigenetic ageing. The researchers wrote, "These findings emphasise the value of adequate vitamin D, not only for lung health but also in slowing age-related processes." They added that people with asthma are more likely to be deficient in vitamin D—a condition linked to more severe disease outcomes such as worse control over symptoms and increased need for inhaled steroids.
The researchers identified miRNAs regulating 248 genes commonly associated with vitamins A and D across both age groups. Further analysis suggested these genes are involved in controlling inflammation and lung function. Secondary analysis revealed changes in specific miRNA expression strongly influence how vitamins A and D affect lung function and epigenetic ageing. "To our knowledge, this is the first study to integrate vitamin A and D levels with lung function and epigenetic markers—miRNA expression and DNA methylation—in both children and adults with asthma," they wrote.
In an editorial linked to the study, Drs. Sze Man Tse and Genevieve Mailhot from CHU Sainte-Justine Research Center cautioned, "While these findings open a novel line of investigation linking vitamin D, biological ageing and lung health, there is a need for further studies to clarify causality." They concluded, "Overall, advancing our understanding of how nutritional exposures impact gene regulation may open new avenues for managing asthma across the lifespan."
