High parathyroid hormone predicts exacerbations in COPD patients with hypovitaminosis D.

Background: Hypovitaminosis D has been linked to deterioration in clinical parameters and lung function in COPD. As a response to low levels of vitamin D serum Parathyroid Hormone (iPTH) is increased in some, but not all, patients. The aim of this study was to determine whether COPD patients with elevated PTH levels are at higher risk of COPD exacerbations and hospitalizations.