Vitamin D and chronic obstructive pulmonary disease

BackgroundEvidence is increasing that suggests an expanded role of vitamin D in health outcomes apart from its classic actions on the bone and calcium homeostasis. Vitamin D deficiency has been associated with some chronic respiratory illnesses; one of them is chronic obstructive pulmonary disease (COPD).ObjectiveThis study was designed to detect vitamin D level among stable COPD patients. The effect of vitamin D supplements (200,000 IU monthly for 6 months) with regular therapy of COPD on COPD outcomes was also evaluated.Patients and methodsPulmonary function test (PFT), COPD assessment test (CAT), 6 min walk test (6MWT), serum 25-hydroxyvitamin D (25-OHD) and ionized calcium were performed on 61 COPD patients (50 males and 11 females, mean age 61.1 years). PFT and clinical assessment were carried out at the start and completion of 6 month treatment among those with vitamin D deficiency. Twenty healthy age-matched and sex matched volunteers were also studied as a control group.ResultsThe distribution of vitamin D status including vitamin D deficiency, vitamin D insufficiency and vitamin D sufficiency was 16.4%, 34.4% and 49.2% respectively among COPD patients.There was no significant improvement of 6MWT, CAT score and PFT among those treated with vitamin D supplements in addition to standard therapy of COPD.ConclusionLow serum level of vitamin D was less common among COPD patients than other studies and correlates with severity of COPD. 6 month supplementation of standard treatment with 200,000 IU monthly of vitamin D did not provide additional clinical benefit among COPD patients.