Vitamins found in carrots, oily fish and eggs could boost lung function in children and adults with asthma, a study has suggested.
About 7.2 million people in the UK have asthma, which can cause wheezing, difficulty breathing, a cough and tight chest, according to Asthma and Lung UK.
There is no cure for asthma, but inhalers and other medication can help control symptoms which can be triggered by exercise, allergens or even changes in weather.
But US researchers, based at Brigham and Women’s Hospital in Boston, have suggested that higher levels of vitamin A and vitamin D in the body are linked to better lung function and even better aging.
“Higher plasma vitamin A is associated with better lung function in children and adults with asthma, while vitamin D shows similar benefits in adults, including slower biological ageing,” study authors concluded.
Previously published research suggests that vitamins A and D both protect against and worsen asthma, as well as influencing lung development, depending on the dose and context.
For the study published in the respiratory journal Thorax, researchers wanted to clarify the role of these vitamins.
Researchers drew on two groups of participants: 1,165 children in the GACRS (Genetic Epidemiology of Asthma in Costa Rica Study); and 1,041 adults in the ODOLLFA (Omic Determinants of Longitudinal Lung Function in Asthma).
Levels of vitamin A and D were measured in all participants, as well as lung capacity.
The findings showed that children and adults with asthma and higher vitamin A levels had better lung function than those with lower levels.
Among adults with asthma, those with higher vitamin D levels of at least 30 ng/ml had better lung function than those with lower levels. They also had less evidence of epigenetic ageing, suggesting that vitamin D may help slow biological ageing, particularly in people with asthma.
For context, 30 ng/ml is considered to be an optimum level of vitamin D to help support healthy bones and muscle. According to the NHS children from the age of one year and adults need 10 micrograms (mcg) of vitamin D a day.
Adults also need between 600 and 700 micrograms of vitamin A, which helps keep the immune system and skin healthy.
In people with asthma, vitamin D deficiency is more common and is associated with more severe disease, higher inhaled steroid need and more frequent sudden worsening of asthma symptoms.
In a linked editorial, Drs Sze Man Tse and Genevieve Mailhot of the CHU Sainte-Justine Research Center, Montreal, and the University of Montreal, warned: “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.”
