25-Hydroxyvitamin D Deficiency Elevates the Risk of COPD Incidence and Mortality: A Large Population-Based Prospective Cohort Study

Background: The association between 25-hydroxyvitamin D (25(OH)D) levels and chronic obstructive pulmonary disease (COPD) remains unclear. The study aims to investigate the association between 25(OH)D concentrations and the incidence and survival of COPD in the U.K. Biobank cohort. Methods: We conducted a cross-sectional analysis using U.K. Biobank data from 328,855 participants with complete 25-Hydroxyvitamin D (25(OH)D). This analysis examined the association between 25(OH)D levels and COPD prevalence via logistic regression. Additionally, we prospectively followed a cohort of 327,871 individuals without baseline COPD. We assessed the risk of incident COPD and survival outcomes in this cohort using multivariable-adjusted Cox proportional hazards models. Kaplan-Meier estimates were used to generate survival curves. Results: The prevalence of COPD was significantly higher in individuals with 25(OH)D deficiency compared to those with a normal level, as evidenced by an adjusted odds ratio (95% confidence interval [CI]) of 1.266(1.206–1.330) for COPD. During the median follow-up period of 15 years (interquartile range: 14–16 years), the overall COPD incidence was 262.3 per 10,000 person years, with higher rates among those with 25(OH)D deficiency (345.2 per 10,000 person years) compared to normal levels (232.6 per 10,000 person years) (p