Asthma is a condition which is characterised by inflammation of the airways. The inflammation is the result of the immune system malfunctioning and reacting to harmless substances such as pollen or dust mites. A new review study by the clinical research body has suggested that Vitamin D may help reduce the risk of asthma attacks [1].  People with asthma who took vitamin D supplements had on average one attack every 4 years where as those that took a placebo experienced one every 2 years.

Previous research funded by Asthma UK and the National Institute for Health Research also suggests that Vitamin D may help in the treatment of severe asthma [2]. The research focused on a molecule known as IL-17A which has been identified as a possible contributor to the malfunctioning of the immune system that occurs in asthma sufferers. In the study the researchers found higher levels of IL-17A within the blood samples of the participants with asthma than in the non-asthmatic patients. They also found that those asthma sufferers who had previously not responded to steroid treatment had the highest levels of IL-17A. Following treatment of the blood samples with vitamin D the levels of IL-17A produced by the blood cells was reduced, including in the samples of those who had not responded to steroid treatment.

These studies provide evidence that Vitamin D could play a role in the treatment of Asthma however much more research and clinical trials are required.

Vitamin D contributes to normal bone and muscle health as well as supporting the immune system. Public Health England (PHE) recently suggested that everyone should be supplementing with 10ug of Vitamin per day. The reason for this is that a lot of people in the UK are not getting enough vitamin D due to a lack of sunlight and the low levels found in food.


[1] Martineau AR, Cates CJ, Urashima M, et al. Vitamin D for the management of asthma. Cochrane Database of Systematic Reviews. Published online September 5 2016

[2] Nanzer AM, Chambers ES, Ryanna K, et al. Enhanced production of IL-17A in patients with severe asthma is inhibited by 1α,25-dihydroxyvitamin D3 in a glucocorticoid-independent fashion. The Journal of Allergy and Clinical Immunology.