Asthma is an inflammatory disease of the airways, causing them to constrict and resulting in attacks of breathlessness and wheezing which can be fatal.
Severe asthma is currently treated with steroid tablets which can have harmful side effects.
Many sufferers have a steroid resistant variation of the condition making it even more difficult to treat and putting them at greater risk of hospitalisation from severe, even life-threatening, asthma attacks.
In a study funded by Asthma UK charity, a team of scientists at King's identified a mechanism through which Vitamin D can reduce asthma symptoms, providing a potential target for future treatments.
IL -17A is a natural chemical which helps to defend the body against infection, but is known to exacerbate asthma and reduce responsiveness to steroids when produced in larger amounts.
The team examined the production of IL-17A and levels of the chemical in cells from 18 steroid resistant asthma patients and 10 patients who responded to steroids, as well as a control group of 10 healthy people.
Results showed that patients with asthma had much higher levels of IL-17A than those without asthma and patients with steroid resistant asthma expressed the highest levels of IL-17A.
Further tests showed that while steroids were unable to lower the production of IL-17A in cells from patients with asthma, vitamin D significantly cut the production of IL-17A in cells from all patients studied.
The results demonstrate that vitamin D could potentially provide an effective add-on treatment for all asthma sufferers, reducing the amount of steroid-based medicines prescribed.
There is growing evidence that vitamin D deficiency may be responsible for triggering a range of diseases, including several cancers.
The body makes most of its vitamin D from sunlight, although oily fish is a good dietary source.
Professor Catherine Hawrylowicz from the Medical Research Council & Asthma UK Centre in Allergic Mechanisms of Asthma at King's, who led the study, said the findings were "very exciting".
- DAILY MAIL