Researchers have identified a way in which vitamin D significantly reduces the symptoms of asthma. The research, published in the Journal of Allergy and Clinical Immunology, may provide a new way to help treat the condition.
Asthma is a condition that affects your airways and lungs, leading to chest tightness, coughing, wheezing, and shortness of breath. Prevalence of asthma has been increasing across all age, gender, and racial groups since the 1980’s.
People with severe asthma are often treated with steroid tablets, which can have severe side effects. There is also a steroid-resistant type of asthma, making it close to impossible to treat. Asthma attacks in these persons can be very serious and possibly life threatening.
Catherine Hawrylowicz of King’s College London and colleagues studied three groups of people: 18 people with steroid-resistant asthma, 10 people with asthma that responded to steroid treatment, and 10 health controls without asthma.
The researchers found that compared with the healthy controls, cells from both asthma groups had higher levels of interleukin-17A (IL-17A). IL-17A protects the body from infection, but is also known to worsen symptoms of asthma and even decrease the beneficial effects of steroids. IL-17A is produced by immune cells called T helper 17 cells, or TH17 cells. The researchers looked at the TH17 cells in each group and examined how they produced the IL-17 and how much they produced.
In addition to discovering the increased IL-17A among asthma patients, they found that vitamin D significantly lowered IL-17A production in cells from all groups. They report that steroids had little effect on IL-17A production.
“These findings are very exciting as they show that vitamin D could one day be used not only to treat people with steroid resistant asthma but also to reduce the doses of steroids in other asthma patients, reducing the risk of harmful side effects,” Hawrylowica explains.
The authors are so intrigued by the results that they are already starting a clinical trial in steroid resistant asthma patients to learn more about vitamin D in the treatment of asthma.
Nanzer AM, et al. Enhanced production of IL-17A in patients with severe asthma is inhibited by 1,25-dihydroxyvitamin D3 in a glucocorticoid independent fashion. The Journal of Allergy and Clinical Immunology, 2013.