Vitamin A and D linked to better lung function in asthma patients

New research published this week in the journal Thorax indicates a link between higher levels of specific vitamins and improved lung function among people with asthma. The study, led by researchers at Brigham and Women’s Hospital in Boston, suggests that circulating levels of vitamin A and vitamin D may influence respiratory health through complex epigenetic mechanisms.

The findings, released on 2 July 2026, represent an effort to clarify the long-debated roles of these micronutrients in respiratory disease. While previous literature has offered conflicting accounts — sometimes suggesting that vitamins might protect against asthma and other times suggesting they could worsen it depending on context and dosage — this study provides a integrated look at how these vitamins interact with gene regulation.

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Study Scope and Methodology

To investigate these connections, the researchers analyzed data from two distinct cohorts:

• The GACRS (Genetic Epidemiology of Asthma in Costa Rica Study): Included 1,165 children with asthma.
• The ODOLLFA (Omic Determinants of Longitudinal Lung Function in Asthma): Included 1,041 adults with the condition.

Researchers measured plasma and serum levels of vitamins A and D alongside epigenetic markers, specifically DNA methylation and microRNA (miRNA) expression. Lung Health was assessed using standard spirometry measures: forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and the FEV:FVC ratio.

Key Findings

The study observed that children and adults with asthma who possessed higher plasma vitamin A levels exhibited superior lung function compared to those with lower levels. In the adult cohort, higher levels of vitamin D, specifically levels of at least 30 ng/ml, were also linked to better lung function. Furthermore, the researchers noted that adults with higher vitamin D levels showed less evidence of epigenetic aging, suggesting the nutrient might assist in slowing biological aging processes in individuals with asthma.

The authors stated:

"These findings emphasise the value of adequate vitamin D, not only for lung Health but also in slowing age-related processes."

Researchers, via Thorax

The analysis also suggested that these effects are mediated by epigenetic mechanisms. Changes in the expression of specific miRNAs and DNA methylation status appeared to influence how these vitamins affect lung physiology. A shared target of interest was the IRF5 gene, where higher vitamin levels were associated with regulatory changes linked to better outcomes.

Expert Perspective and Future Directions

In a linked editorial, Dr. Sze Man Tse and Dr. Genevieve Mailhot of the University of Montreal highlighted the nuance of these results. While they acknowledged the findings open a novel line of investigation into biological aging and lung health, they cautioned that the study does not prove that simply taking supplements will improve lung function.

"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."

Dr. Sze Man Tse and Dr. Genevieve Mailhot, via Thorax

The researchers themselves acknowledged the need for future interventional studies to determine whether dietary modifications or targeted supplementation can provide therapeutic benefits for asthma management. This research follows a history of varying results in the field; for instance, a 2016 Cochrane review suggested vitamin D supplementation might cut the risk of severe asthma attacks, but an updated 2023 review by the same authors did not find sufficient evidence to support that conclusion for reducing exacerbations or improving asthma control.

What to Watch Next

As the scientific community reviews these findings, medical professionals are focusing on the following areas to determine the path forward for patient care:

Area of Investigation	Goal
Causality Studies	Moving from observational data to clinical trials to see if supplements improve lung function.
Epigenetic Mediation	Further exploring how IRF5 gene regulation specifically impacts asthma severity.
Personalized Nutrition	Determining if individual vitamin profiles can predict better responses to specific asthma treatments.