ScienceDaily reports that low vitamin D levels are associated with lower lung function and greater medication use in children with asthma. Researchers at National Jewish Health published these findings in the Journal of Allergy & Clinical Immunology, also reporting that vitamin D enhances the activity of corticosteroids, which are the most effective type of medication for treating asthma.
Dr. Daniel Searing says, ‘Asthmatic children in our study who had low levels of vitamin D were more allergic, had poorer lung function and used more medications. Conversely, our findings suggest that vitamin D supplementation may help reverse steroid resistance in asthmatic children and reduce the effective dose of steroids needed for our patients.’
The study involved checking the medical records of 100 pediatric asthma patients who were referred to National Jewish Health. Of these 100, 47 had insufficient vitamin D levels and 17 had deficient levels; interestingly, these insufficient and deficient levels are consistent with levels found in the general population.
The connection between vitamin D and allergies is through IgE, an allergy marker: Low vitamin D levels generally indicate higher IgE levels. Accordingly, low vitamin D levels were associated with allergies to specific indoor allergens. Furthermore, low vitamin D levels were also linked to low FEV1, the amount of air a person can exhale in one second, and lower FEV1/FVC, another measure of lung function, ScienceDaily explains. Not surprisingly, low vitamin D levels with its tendency to signal increased allergies and decreased lung function, is also connected to greater use of oral steroids and long-acting beta agonists.
The finding related to increased medication use, senior author Donald Leung, MD, PhD explains, has ‘two possible explanations. It could be that lower vitamin D levels contribute to increasing asthma severity, which requires more corticosteroid therapy. Or, it may be that vitamin D directly affects steroid activity, and that low levels of vitamin D make the steroids less effective, thus requiring more medication for the same effect.’
Researchers conducted further studies that indicated corticosteroid action is enhanced by vitamin D