Effects of Vitamin D Supplementation on Exacerbation in Patients with Severe COPD

Abstract

Introduction: Results from several studies indicated that vitamin D plays a role in a variety of immunologic processes such as modulation of inflammatory pathways and susceptibility to infections. Aim of the study: To assess the effects of vitamin D supplementation on bacterial exacerbations in patients with severe chronic obstructive pulmonary disease (COPD) with low vitamin D serum level. Methods: We performed an observational, non-randomized, open-label study including 36 patients with severe COPD who besides the recommended chronic treatment for stable disease took oral vitamin D supplementation in dose of 2000 IU daily during a six month-period (Group 1). In addition, 35 patients with severe COPD, matched to the study subjects of the Group 1 by sex, age and serum vitamin D level, who did not receive vitamin D supplementation served as controls (Group 2). Analysis of exacerbations, including their incidence and duration, as well as incidence of relapses and duration of exacerbation-free interval, was done for each study subjects based on daily diary cards maintained by all of them during the mentioned period. Results: Mean serum vitamin D levels at baseline did not differ significantly between examined groups (21.7 vs. 22.1; P = 0.457). At the end of the study its mean level was significantly higher in the Group 1 as compared to Group 2 (30.1 vs. 23.4; P = 0.000). Mean number of the first exacerbation over a six month-period was significantly lower in the Group 1 as compared to their mean number in the Group 2 (0.8 vs. 0.9; P = 0.001). Mean duration of the first exacerbation in the Group 1 (6.7 ± 1.2 days) was significantly lower as compared to its mean duration in the Group 2 (7.2 ± 1.3 days) (P = 0.033). Mean number of relapses registered in the Group 1 (0.2 ± 0.1) was significantly lower than its mean number registered in the Group 2 (0.4 ± 0.2) (P = 0.000). Mean exacerbation-free interval in the Group 1 (39.3 ± 10.1 days) was significantly longer than in the Group 2 (33.7 ± 11.8 days) (P = 0.052). Conclusion: Our findings indicated that vitamin D supplementation may impact the incidence and duration of bacterial exacerbations in patients with COPD. There is a need of further studies to elucidate the role of vitamin D supplementation on the course of COPD.