Investigators in Belgium were testing the ability of vitamin D to control flare-ups in chronic obstructive pulmonary disease or COPD. Previous research has shown that nearly 75 percent of patients with COPD are deficient in vitamin D. Since this vitamin can ease inflammation it had been hoped that monthly doses of 100,000 IU of vitamin D would reduce inflammation in the airways. Patients on vitamin D, however, were no less likely to suffer acute breathing difficulties compared to those on placebo.
[Annals of Internal Medicine, online January 17, 2012]