Chronic obstructive pulmonary disease (COPD) is a lung disorder that is described by permanent, irreversible obstruction of airflow and an abnormal inflammatory response. COPD places a huge burden on both the patient and the healthcare system. Several studies now exist that link COPD to vitamin D deficiency. It is thought that lower serum concentrations of vitamin D can cause a reduction in lung function due to its role in the innate and adaptive immune responses. This meta-analysis evaluates whether or not the use of supplemental vitamin D (I) in individuals diagnosed with COPD who have a clinical vitamin D deficiency (P), provides improved symptomatic relief (O) compared to the use of standard therapy alone (C)
