Association Between Vitamin D Levels and Infective Exacerbation of Chronic Obstructive Pulmonary Disease (COPD)

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is a major global health burden, with exacerbations significantly worsening patient outcomes and increasing healthcare utilization. Despite abundant sunlight in many regions, vitamin D deficiency remains prevalent among COPD patients, and its role in disease progression and exacerbation risk is not fully understood. Objective: This study aimed to evaluate the association between serum vitamin D levels and the frequency of infective exacerbations in COPD patients, as well as the relationship of vitamin D status with disease severity and systemic inflammation. Methods: A cross-sectional study was conducted at the Pulmonology Department of Khyber Teaching Hospital, Peshawar, enrolling 123 COPD patients aged 30–80 years using consecutive sampling. Exclusion criteria included metabolic bone disease, severe comorbidities, other chronic lung diseases, pregnancy, or lactation. Data on demographics, smoking, comorbidities, lung function, vitamin D, and C-reactive protein (CRP) were collected. Vitamin D was categorized as deficient (<20 ng/mL), insufficient (20–29 ng/mL), or sufficient (≥30 ng/mL). Outcomes included COPD severity (GOLD criteria), annual infective exacerbations, and CRP. Statistical analysis utilized SPSS v25, with Chi-square, ANOVA, and regression modeling; p-values <0.05 were significant. Ethical approval was obtained per the Helsinki Declaration. Results: Vitamin D deficiency was observed in 42.3% of patients, with deficiency significantly associated with advanced COPD stage (OR=2.86, 95% CI: 1.11–7.35, p=0.021), increased exacerbations (2.7 vs. 1.5/year, p=0.004, Cohen’s d=1.17), and higher CRP (9.4 vs. 5.6 mg/L, p=0.008). Smoking status further compounded disease severity (p=0.037). Conclusion: Vitamin D deficiency is highly prevalent and independently associated with increased COPD severity, higher frequency of infective exacerbations, and greater systemic inflammation, highlighting the importance of vitamin D assessment and targeted supplementation in COPD management to improve patient outcomes.