Abstract
This review examines the efficacy of vitamin D supplementation in preventing exacerbations in patients with chronic obstructive pulmonary disease (COPD), a major global contributor to morbidity and mortality. Exacerbations, often caused by infections, significantly worsen outcomes and elevate healthcare costs. Given its immunomodulatory properties, vitamin D has been hypothesized to reduce exacerbations, particularly in populations with vitamin D deficiency. A systematic search of multiple databases was performed in February 2024 and evidence was synthesized from four systematic reviews with meta-analyses and one recent randomized controlled trial. Findings indicate that vitamin D supplementation does not generally reduce exacerbation rates in COPD patients. However, in patients with baseline 25-hydroxyvitamin D (25(OH)D) serum levels below 10 ng/mL, one meta-analysis reported a significant (p=0.006) reduction in moderate-to-severe exacerbations following supplementation. Variability in study designs, dosages, and follow-up durations limit the generalizability of these findings. Nevertheless, clinical guidelines recommend screening and supplementing vitamin D in COPD patients, particularly those with severe deficiency. Clinicians should consider the low cost and risk of vitamin D supplementation and its potential benefits in reducing exacerbations in such patients.