A a study published in the May 1st issue of the American Journal of Respiratory and Critical Care Medicine has revealed some new information on a possible link between vitamin D deficiency and allergy & asthma severity. In this study the serum levels of approximately 600 Costa Rican children were linked to several indicators of allergy and asthma severity, including hospitalizations for asthma, use of inhaled steroids and total IgE levels. Costa Rica is known to have a high prevalence of asthma.
Harvard Medical School & colleagues assessed each child participant for allergic markers (allergen-specific and general sensitivity tests), assessed their lung function & circulating vitamin D levels.
Researchers found that the children who had the lower vitamin D levels were significantly more likely to have been in the hospital for asthma the previous year. These same children also ”tended to have airways with increased hyperreactivity and were likely to have used more inhaled corticosteroids, all signifying higher asthma severity. These children were also significantly more likely to have several markers of allergy, including dust-mite sensitivity.” Juan Celedon, MD, DrPH and Augusto Litonjua, MD, MPH, of Harvard Medical School said:
“To our knowledge this is the first study to demonstrate an inverse association between circulating levels of vitamin D and markers of asthma severity and allergy. While it is difficult to establish causation in a cross-sectional study such as this, the results were robust even after controlling for markers of baseline asthma severity. This study suggests that there may be added health benefits to vitamin D supplementation” said Dr. Celedón. Current recommendations for optimal vitamin D levels are geared toward preserving bone health, such as preventing rickets in children and osteoporosis in adults.”
“This study also provides epidemiological support for a growing body of in vitro evidence that vitamin D insufficiency may worsen asthma severity, and we suspect that giving vitamin D supplements to asthma patients who are deficient may help with their asthma control. Whether vitamin D supplementation can prevent the development of asthma in very young children is a separate question, which will be answered by clinical trials that are getting under way.”