Skip to content

    Asthma Health Center

    Font Size
    A
    A
    A

    Vitamin D Supplements May Not Help Ease Asthma

    Study did suggest the nutrient might help lower patients' dependence on inhaled steroids

    WebMD News from HealthDay

    By Robert Preidt

    HealthDay Reporter

    SUNDAY, May 18, 2014 (HealthDay News) -- Vitamin D supplements do little to help control asthma, a new study found, although they might help cut the level of medication some patients need.

    "Previous studies suggested that if you have asthma and low levels of vitamin D in the blood, you have worse lung function, more asthma attacks and more emergency room visits than asthma patients with higher vitamin D levels," Dr. Mario Castro, a professor of pulmonary and critical care medicine at Washington University School of Medicine in St. Louis, explained in a university news release.

    So, his team decided to conduct "the first randomized controlled trial to investigate whether taking vitamin D supplements can improve asthma control," he said.

    The study included more than 400 adult asthma patients at nine major medical centers in the United States. All of them had mild to moderate asthma and what was considered deficient blood levels of vitamin D.

    The patients were divided into two groups: One group took an initial dose of 100,000 international units (IUs) of vitamin D3, followed by daily doses of 4,000 IUs, while the second group took a placebo.

    The two groups showed no differences in all major measures of asthma control, such as the number of asthma attacks, the need for emergency care or the number of treatment failures that resulted in having to take more medication, the study found. Patients taking vitamin D also did not report improved quality of life.

    The researchers did find that patients taking vitamin D were more successful in reducing their daily dosages of inhaled steroid medications. By the end of the 28-week study, the average daily doses were 111 micrograms for those in the vitamin D group versus 126 micrograms for those in the placebo group.

    "The difference was small -- 15 micrograms of steroid per day -- but statistically significant," Castro said. "Over the long term, even that small amount may have an important impact on reducing side effects of inhaled steroids. Although inhaled steroids work very well in controlling asthma, patients don't like them because they cause weight gain and increase the risk of diabetes and high blood pressure. Anything we can do to reduce the amount they need is important."

    The study was published online May 18 in the Journal of the American Medical Association and is also being presented the same day at the annual meeting of the American Thoracic Society, in San Diego.

    When Is Your Asthma Worse?

    When Is Your Asthma Worse?

    Take the WebMD Asthma assessment to get Personalized Action Plan

    Start Now

    Today on WebMD

    Lung and bronchial tube graphic
    5 common triggers.
    group jogging in park
    Should you avoid fitness activities?
     
    asthma inhaler
    Learn about your options.
    man feeling faint
    What’s the difference?
     
    Madison Wisconsin Capitol
    Slideshow
    woman wearing cpap mask
    Article
     
    red wine pouring into glass
    Slideshow
    Woman holding inhaler
    Quiz
     
    Man outdoors coughing
    Article
    Lung and bronchial tube graphic
    Article
     
    10 Worst Asthma Cities
    Slideshow
    runner
    Article