A comprehensive Cochrane review has found that vitamin D supplementation provides no significant benefit for managing chronic obstructive pulmonary disease (COPD) or reducing the frequency of exacerbations. The meta-analysis, encompassing 10 double-blind, randomized, placebo-controlled trials with a total of 1372 adults, challenges the notion that vitamin D can alleviate COPD symptoms or prevent acute episodes.
The study, published in the Cochrane Database of Systematic Reviews, assessed the effects of vitamin D on COPD exacerbations and symptoms. The primary outcome was the rate of moderate or severe exacerbations requiring systemic corticosteroids, antibiotics, or both. Secondary outcomes included the proportion of participants experiencing one or more exacerbations, changes in forced expiratory volume in one second (FEV1), serious adverse events, mortality, and quality of life.
The analysis revealed that vitamin D supplementation did not significantly reduce the rate of moderate or severe exacerbations (rate ratio 0.98, 95% CI 0.86 to 1.11; high-certainty evidence). Furthermore, it showed little to no effect on the proportion of participants experiencing one or more exacerbations (odds ratio 0.94, 95% CI 0.72 to 1.24; high-certainty evidence).
Regarding lung function, vitamin D probably results in little to no difference in the inter-arm mean change in FEV1 (% predicted) (mean difference 2.82 higher in intervention arm, 95% CI -2.42 to 8.06; moderate-certainty evidence). There was also probably no effect of vitamin D on the incidence of serious adverse events due to any cause (OR 1.19, 95% CI 0.82 to 1.71; moderate-certainty evidence). Vitamin D may have little to no effect on mortality (OR 1.13, 95% CI 0.57 to 2.21; low-certainty evidence) or quality of life (narrative findings; low-certainty evidence).
The included studies primarily involved participants with mild to moderate COPD. Profound vitamin D deficiency (25-hydroxyvitamin D (25(OH)D) < 25 nmol/L) at baseline was rare among participants contributing data to subgroup analysis.
The researchers suggest that further research is needed to evaluate the potential benefits and harms of vitamin D supplementation in COPD patients with very low or very high baseline vitamin D levels, as the current evidence for these groups is of low certainty. The study underscores the importance of evidence-based approaches to COPD management and highlights the need for caution when considering vitamin D supplementation as a routine intervention.
