Vitamin D Deficiency Aggravates Asthma

Asthmatics with vitamin D deficiency are significantly more susceptible to acute asthma attacks, according to research recently published in Allergy.

“Vitamin D has significant immunomodulatory effects and, as such, was believed to have an effect on asthma—an immunologically mediated disease,” said study author and Tel Aviv University researcher Ronit Confino-Cohen, MD, in a press release. “But most of the existing data regarding vitamin D and asthma came from the pediatric population and was inconsistent. Our present study is unique because the study population of young adults is very large and ‘uncontaminated’ by other diseases.”

For the study, Dr. Confino-Cohen and her team of researchers measured the vitamin D levels of 307,900 patients between 2008 and 2012, taking into account key predictors of asthma, such as smoking and obesity. Of the roughly 21,000 patients with physician-diagnosed asthma, those with a vitamin D deficiency were 25% more likely than other asthmatics to have experienced at least 1 acute attack in the recent past and were at a higher risk for an asthma attack.

Based on those findings, the researchers recommended that patients whose asthma cannot be controlled with existing treatments undergo vitamin D level screening. Because the study authors concluded that boosting vitamin D levels could help manage asthma attacks, they suggested that supplementation might be necessary for those with vitamin D deficiency.

“We know a lot about this disease and many therapeutic options are available, so it’s quite frustrating that the prevalence of asthma is not decreasing and many patients suffer exacerbations and significant impairment in their quality of life,” Dr. Confino-Cohen said. “Increasing vitamin D levels is something we can easily do to improve patients’ quality of life.”

However, a study published on May 28, 2014, in JAMA claimed that vitamin D₃ supplementation does not improve asthma symptoms or treatment in vitamin D—deficient asthmatics.

In adults with persistent asthma and lower vitamin D levels, treatment with vitamin D₃ did not reduce the rate of first treatment failure or exacerbation, the authors of that research concluded. “These findings do not support a strategy of therapeutic vitamin D₃ supplementation in patients with symptomatic asthma.”