According to a recent study, Vitamin D deficiency can be linked to asthma. This makes the populations of sunlight deficient regions more prone to this disease of the respiratory tract.
In the study, published in the American Journal of Respiratory and Critical Care Medicine, Dr. Juan C. Celedon at Boston's Brigham and Women's Hospital and co-investigators examined the association between vitamin D levels and markers of asthma severity and allergy in 616 asthmatic children between the ages of 6 and 14 from Costa Rica. They found that 175 had insufficient levels of vitamin D.