Higher Vitamin A and Vitamin D Levels Associated With Better Lung Function: Study
USA: Researchers found in an observational study that higher vitamin A levels were associated with better lung function in both adults and children. In contrast, higher vitamin D levels were associated with improved lung function in adults. Further analysis suggested that microRNAs (miRNAs) and DNA methylation may partially mediate these associations. However, the findings do not establish that vitamin supplementation or dietary modifications improve lung function, highlighting the need for further research to determine causality and potential therapeutic benefits.
The findings, published in Thorax, come from a study led by Rinku Sharma from the Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA, and colleagues. The researchers investigated how vitamins A and D relate to lung function, epigenetic ageing, and regulatory epigenetic mechanisms in children and adults with asthma.
For the study, the researchers analyzed data from 1,165 children and 1,041 adults with asthma from two independent cohorts. They assessed blood vitamin A and D levels, microRNA profiles, DNA methylation patterns, lung function, and epigenetic ageing. In adults, mediation analyses examined whether DNA methylation and microRNAs partly explained the association between vitamin levels and lung function.
Key findings:
- Higher vitamin A levels were associated with better lung function in children with asthma, including higher forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC).
- Vitamin D levels were not significantly associated with lung function in children.
- In adults, higher levels of both vitamin A and vitamin D were associated with improved FEV₁ and FVC.
- Only vitamin A was associated with a higher FEV₁/FVC ratio in adults.
- Adults with sufficient vitamin D levels had lower epigenetic ageing than those with lower vitamin D levels.
- Higher vitamin A and D levels were associated with reduced DNA methylation at regulatory sites in the IRF5 gene, a pattern linked to better lung function and slower epigenetic ageing.
- Distinct vitamin-associated microRNAs (miRNAs) involved in immune and cell-cycle pathways were identified.
- Mediation analyses suggested that DNA methylation and miRNAs partially explained the association between vitamin levels and lung function.
The researchers acknowledged the study's observational design as a limitation, meaning it cannot establish causality. They emphasized that the findings do not support vitamin supplementation or dietary changes to improve lung function and called for further clinical and mechanistic studies.
Overall, the findings suggest that higher vitamin A levels are associated with better lung function in both children and adults with asthma, while vitamin D showed similar associations only in adults. The study also highlights DNA methylation and miRNA regulation as potential mechanisms linking vitamin status to lung health, warranting further investigation for personalized asthma care.
Reference:
Sharma R, Kachroo P, Mendez KM, et alThe impact of vitamins A and D on lung function and regulatory epigenetics in adult and childhood asthmaThorax Published Online First: 30 June 2026. doi: 10.1136/thorax-2025-223756
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