Serum 25-Hydroxyvitamin D Status and Its Association with Clinical Characteristics and Coronary Angiographic Findings in Patients Undergoing Coronary Angiography

Background: The relationship between circulating 25-hydroxyvitamin D [25(OH)D] and coronary artery disease (CAD) remains uncertain. This study assessed serum 25(OH)D concentrations and their distribution across demographic, clinical, lifestyle, therapeutic, and angiographic variables. Methods: A prospective observational study was conducted from April to September 2023 at Dr. Pinnamaneni Siddhartha Institute of Medical Sciences and Research Foundation, Andhra Pradesh, India. Forty-seven consecutive patients undergoing evaluation for suspected or established CAD with coronary angiography were enrolled. Serum 25(OH)D was categorized as ≥30, 20–<30, 10–<20, and <10 ng/mL. Categorical associations were assessed using the Fisher–Freeman–Halton exact test; Kruskal–Wallis, Mann–Whitney U, and Welch’s t-tests were used as appropriate. Results: Mean 25(OH)D was 27.23 ± 8.83 ng/mL (range, 11.58–53.54); 70.2% had concentrations <30 ng/mL, with 20–<30 ng/mL being most frequent (53.2%). Category distribution differed significantly by age (p=0.043) and smoking (p=0.005), but not sex, alcohol use, diabetes, or hypertension. Concentrations were not significantly associated with clinical diagnosis (p=0.389), angiographic category (p=0.563), sunlight exposure (p=0.215), or vitamin D-containing food intake (p=0.507). Statin users had higher concentrations than non-users (28.66 ± 8.67 vs 19.09 ± 9.38 ng/mL; p=0.036). Conclusion: Vitamin D concentrations below 30 ng/mL were frequent, with age and smoking associated with category distribution. No significant association with angiographic findings was observed. Given the small sample and observational design, findings are exploratory and do not establish causality.