Association between Vitamin D Deficiency and Lower Respiratory Tract Infections among Sudanese Patients, Sudan

Abstract

Background: Lower respiratory tract infections represent a significant cause of hospital admissions, patient morbidity, and mortality worldwide. Vitamin D plays a crucial regulatory role in immune function, and inadequate levels have been associated with increased vulnerability to respiratory pathogens and more severe clinical courses. Objective: This study aimed to evaluate the relationship between vitamin D deficiency and lower respiratory tract infections in patients admitted to Atbara Teaching Hospital during 2026. Methods: A hospital-based observational analytical study was conducted over six months (February to July 2026) at Atbara Teaching Hospital in Sudan. The study enrolled 50 adult patients admitted with lower respiratory tract infections. Data were collected using a structured questionnaire and case record form. Serum 25-hydroxyvitamin D levels were measured, and vitamin D status was categorised as deficient, insufficient, or sufficient. Disease severity was evaluated using the CURB-65 scoring system. Statistical analysis was performed using SPSS, with statistical significance defined as p < 0.05. Results: The mean serum 25-hydroxyvitamin D level was 20.60 ± 15.69 ng/mL, ranging from 2.00 to 55.00 ng/mL. Vitamin D deficiency was identified in 23 patients (46.0%), insufficiency in 12 (24.0%), and sufficient levels in 15 (30.0%). Cough was reported by all participants (100.0%), followed by fever (76.0%) and sputum production (72.0%). Hypertension was the most common comorbidity (36.0%), followed by diabetes mellitus (32.0%). Vitamin D status demonstrated significant associations with CURB-65 score (p = 0.012), length of hospital stay (p = 0.021), and the presence of comorbidities (p = 0.007). Although ICU admission, sepsis, septic shock, acute respiratory distress syndrome, and mortality were not significantly associated with vitamin D status, these adverse outcomes occurred more frequently among vitamin D-deficient patients. Conclusion: Vitamin D deficiency was highly prevalent among patients with lower respiratory tract infections and demonstrated significant associations with increased disease severity, prolonged hospitalisation, and comorbid conditions. Assessment of vitamin D status should be considered in admitted patients, particularly those presenting with severe illness or chronic comorbidities.