Volunteers needed for study of vitamin D’s role in asthma

Researchers at Washington University School of Medicine in St. Louis are seeking volunteers for a study investigating whether taking vitamin D can make asthma medication more effective.

A number of studies have linked low vitamin D levels in asthma patients to decreased lung function and increased risk of asthma attacks, says asthma specialist Mario Castro, MD, professor of medicine, who is leading the study.

“We are taking the next step — trying to replace vitamin D in individuals with asthma who have low levels of the vitamin and poorly controlled asthma despite taking a low dose inhaled steroid,” Castro says. “The vitamin D insufficiency may explain why their medications don’t work well.”


Study participants must be 18 or older and have a physician’s diagnosis of asthma. They also must have been taking some type of therapy to control their asthma for at least one year. Volunteers will begin with two screening visits to learn about the study, determine baseline vitamin D levels and how well their asthma is controlled. Volunteers who have insufficient vitamin D levels and asthma that is not well controlled are eligible to enroll in the main part of the study.

All participants will receive a one-time dose of either 100,000 international units of vitamin D3 or a placebo. Afterward, participants will take a daily capsule that contains either 4,000 units of vitamin D3 or a placebo. Neither participants nor investigators will know who receives the vitamin and who receives a placebo until the end of the study.

To minimize differences in treatments used to control asthma symptoms, all participants will receive the inhaled steroid ciclesonide, also known by its brand name Alvesco. Likewise, all patients will receive the rescue medication, levalbuterol, also known by its brand name Xopenex.

Throughout the study, participants will be asked to use a device to monitor their lung function at home and to keep a diary of asthma symptoms. Participants will have 11 clinic visits that may last from 45 minutes to a few hours. Investigators will take patients’ medical history and perform physical exams at the early visits. In later visits, they will monitor the patients’ calcium levels in the blood and urine, perform allergy skin tests and give breath challenge tests to track how participants are doing. All participants will be compensated for their time.

The study is supported by the National Heart, Lung, and Blood Institute (NHLBI), which is a part of the National Institutes of Health (NIH). Washington University School of Medicine is a member of the NHLBI Asthma Network, known as AsthmaNet, a network of 17 sites across the country investigating asthma in children and adults.

For more information, contact PeChaz Clark at (314) 747-3759, toll-free at (866) 362-5656, or by email at clarkp@wustl.edu.

Washington University School of Medicine’s 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked fourth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.