Vitamin D could be a new weapon against severe asthma

A potential new weapon against acute asthma is readily available and inexpensive and has few adverse effects if taken in the correct dosage. Pediatricians could soon be adding vitamin D supplementation to their asthma-fighting arsenals.

A new study suggests that treating vitamin D deficiency in children with severe, therapy-resistant asthma (STRA) could help prevent or reduce structural changes that occur in the airway smooth muscle, which could relieve some asthma symptoms and improve overall lung function. British researchers cautioned that intervention studies are required to determine the exact mechanism between vitamin D and airway changes.

Researchers evaluated 86 children (mean age, 11.7 years), 36 of them with STRA, 26 with moderate asthma, and 24 controls without asthma for vitamin D levels, lung function, medication usage, and symptom exacerbations. Tissue samples were reviewed for the STRA group. As many as 10% of asthmatic children have STRA and do not respond to standard treatment, including corticosteroids, according to the study.

"This study clearly demonstrates that low levels of vitamin D are associated with poorer lung function, increased use of medication, worse symptoms, and an increase in the mass of airway smooth muscle in children with STRA," said Atul Gupta, MRCPCH, MD, a researcher from Royal Brompton Hospital and the National Heart and Lung Institute at Imperial College and King's College in London. "It is therefore plausible that the link between airway smooth muscle mass and lung function in severe asthma may be partly explained by low levels of vitamin D."

Previous studies of pediatric asthma have looked at the relationship of airway smooth muscle mass with poorer lung function, and some in vitro studies have established a connection between levels of vitamin D and the proliferation of airway smooth muscle, but this study is the first to show a link between vitamin D levels and the pathophysiology of children with STRA.

"The results of this study suggest that lower levels of vitamin D in children with STRA contribute to an increase in airway smooth muscle mass, which could make breathing more difficult and cause a worsening of asthma symptoms," Gupta said. The research could eventually lead to the use of vitamin D supplementation in treatment-resistant asthma.

"The determination of the exact mechanism between low vitamin D and airway changes that occur in STRA will require intervention studies," Gupta added. "Hopefully, the results of this and future studies will help determine a new course of therapy that will be effective in treating these children."

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