Vitamin D may help control asthma

VANCOUVER, British Columbia, Sept. 9 (UPI) -- A review of 60 years of studies suggests vitamin D added to an asthma action plan may improve asthma control, U.S. and Canadian researchers find.

Lead author Dr. Manbir Sandhu, a Vancouver allergist, and colleagues conducted a review of the research on asthma and vitamin D and found vitamin D deficiency is associated with increased airway hyper-responsiveness, lower lung functions and inferior asthma control.

In addition, the researchers say vitamin D deficiency is more common in those who are obese, have African-American ethnicity and are from westernized countries -- reflecting a higher-risk population for asthma.

"There is a possible cause-and-effect relationship between vitamin D deficiency and uncontrolled asthma," Sandhu says in a statement. "Evidence suggests that vitamin D has a number of biologic factors that are important in regulating key mechanisms in asthma."

The findings are published in the Annals of Allergy, Asthma & Immunology.