Chronic Obstructive Pulmonary Disease (COPD) is characterized by diseases such as Bronchitis and Emphysema, where breathing becomes more difficult as the airways are inflamed, blocked with mucus and ultimately permanently damaged. The problem is usually caused by cigarette smoking, although exposure to industrial chemicals, pollutants or smoke inhalation may also be involved.
It was thought that vitamin D might be effective in helping to ease the condition, because most patients with COPD have vitamin D deficiency, but new research published in Annals of Internal Medicine suggests otherwise.
The study was carried out by scientists at The University Hospitals Leuven, Leuven, Belgium and funded by Applied Biomedical Research Program, Agency for Innovation by Science and Technology. Wim Janssens, MD, PhD, of University Hospitals Leuven, Belgium, and colleagues gave test subjects monthly doses of 100,000 IU or more than 3,200 IU per day, where the standard recommended dose is only 600 IU daily to 800 IU daily for lactating women and the elderly. However no marked change or improvement was seen in the patients' symptoms.
In total, 182 patients were part of the trial and all had moderate to severe COPD and recent history of exacerbations. The primary outcome was time to first exacerbation. Secondary outcomes were exacerbation rate, time to first hospitalization, time to second exacerbation, quality of life, and death.
Patients' vitamin D level was measured by blood test throughout the trial, and patients were given either 100,000UI of vitamin D per month for a year, or a placebo. The researchers then recorded whether patients had exacerbations of COPD during the study.
Although patients receiving the supplements of vitamin D showed increased levels in their blood, the number of exacerbations over the course of the year was no different to those on the placebo. Researchers did note that a small group of patients that started the trial with extremely low vitamin D levels may have showed some improvement, but results were inconclusive.
They recommended a further research to investigate whether patients with very low vitamin D levels may benefit from supplements, but so far it appears in general that most patients won't benefit greatly, if at all, and certainly Vitamin D supplements are not an effective way to prevent exacerbation of COPD.
Dr. Wim Janssens, from the respiratory division at University Hospital Gasthuisberg in Leuven, the lead investigator said :
"There are studies showing that patients with vitamin D deficiency are more susceptible to different inflammatory, infectious and autoimmune diseases, and most likely COPD ... [however] ... Vitamin D restoration to normal levels in COPD patients does not reduce the number of exacerbations, does not reduce the infections and inflammation."
Written by Rupert Shepherd