Abstract
The risk of acute respiratory tract infections is particularly pronounced in patients deficient in 25-hydroxyvitamin D (25(OH)D). With respect to COVID-19, there are conflicting evidence on the association of 25(OH)D levels with disease severity. We undertook this study to evaluate the 25(OH)D status in COVID-19 patients admitted in Karachi, Pakistan, and associated vitamin D deficiency with primary outcomes of mortality, length of stay, intubation, and frequency of COVID-19 symptoms. A total of 91 patients were evaluated for 25(OH)D status during their COVID-19 disease course. 25-hydroxyvitamin D levels were classified as deficient (< 10 ng/mL), insufficient (10-30 ng/mL), or sufficient (> 30 ng/mL). The study population comprised 68.1% males (N = 62). The mean age was 52.6 ± 15.7 years. Vitamin D deficiency was significantly associated with intensive care unit (ICU) admission (RR: 3.20; P = 0.048), invasive ventilation (RR: 2.78; P = 0.043), persistent pulmonary infiltrates (RR: 7.58; P < 0.001), and death (RR: 2.98; P < 0.001) on univariate Cox regression. On multivariate Cox regression, only death (RR: 2.13; P = 0.046) and persistent pulmonary infiltrates (RR: 6.78; P = 0.009) remained significant after adjustment for confounding factors. On Kaplan Meier curves, vitamin D deficient patients had persistent pulmonary infiltrates and a greater probability of requiring mechanical ventilation than patients with 25(OH)D ≥ 10 ng/mL. Mechanical ventilation had to be initiated early in the deficient group during the 30-day hospital stay (Chi-square: 4.565, P = 0.033). Patients with 25(OH)D ≥ 10 ng/mL also demonstrated a higher probability of survival than those with 25(OH)D concentrations < 10 ng/mL. 25-hydroxyvitamin D deficient population had longer hospital stays and worse outcomes.