TEHRAN (Press Shia Agency) – Researchers at the University of Colorado Anschutz Medical Campus found that high doses of vitamin D reduce the incidence of acute respiratory illness (ARI) in older, long-term care residents.

The findings of the clinical trial, published in the Journal of the American Geriatrics Society, could help reduce one of the leading causes of serious illness, debilitation and death among patients in nursing homes and other long-term care facilities.

"After studying these patients for a year, we found a 40 percent reduction in acute respiratory illness among those who took higher doses of vitamin D," said the study's lead author, Adit Ginde.

"Vitamin D can improve the immune system's ability to fight infections because it bolsters the first line of defense of the immune system."

Ginde said in older people that first line of defense is often impaired. But vitamin D can reinforce it and prevent illnesses like pneumonia, influenza and bronchitis.

It may also prevent infections and exacerbations of Chronic Obstructive Pulmonary Disease (COPD) like emphysema.

At the same time, Ginde found that those who received higher doses of vitamin D also saw an increase in falls. The falls were lower in those given smaller doses rather than higher monthly doses of vitamin D.

The clinical trial, the first to examine vitamin D's impact on respiratory infections in nursing home residents, looked at 107 patients with an average age of 84 over a 12 month period. Of those, 55 received high doses of vitamin D or 100,000 units monthly (averaging 3,300-4,300 units daily). And 52 received lower doses averaging between 400-1,000 units daily. Those with higher doses saw ARIs cut nearly in half. They also had over double the incidence of falls, the study said.