Abstract: C62 EXPANDING OUR INSIGHT INTO COVID-19 / Thematic Poster Session / Tuesday, May 17/09:30 AM-03:45 PM / Area D, Hall F (North Building, Exhibition Level), Moscone Center Vitamin D Deficiency and Thrombosis in Hospitalized SARS-CoV-2 Patients with Suspected Pulmonary Embolism S. V. Charkowick, C. N. Logothetis, A. Jordan, C. Hanna, S. Zhang, K. Tsay, E. Coughlin, R. Mhaskar, T. A. Weppelmann, A. Oxner; USF Health Morsani College of Medicine, Tampa, FL, United States. Corresponding author's email: scharkowick@usf.edu RATIONALE Despite the use of anticoagulation therapy in hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there are high rates of pulmonary embolism (PE) and deep vein thrombosis (DVT). Vitamin D is a potent immunomodulator with anticoagulative properties that may play a role in suppressing the formation of thrombotic emboli. Supplementation with vitamin D has an excellent safety profile and provides protection against acute respiratory infections. Recent studies have indicated that there is a positive association between vitamin D deficiency and the severity of SARS-CoV-2. However, the relationship between vitamin D deficiency and the incidence of thrombotic events in patients with SARS-CoV-2 has not been thoroughly investigated. The main objective of this study was to evaluate the association between vitamin D deficiency and thrombotic events (PE or DVT) in hospitalized SARS-CoV-2 patients. METHODS This was a retrospective, cross-sectional study including 208 hospitalized SARS-CoV-2 patients who received a computed tomographic pulmonary angiography (CTPA) based on clinical suspicion of PE between January 1, 2020, and February 5, 2021. A serum vitamin D level of <20 ng/mL was used to categorize vitamin D deficiency. Nonparametric tests and multivariate binary logistic regression were used to evaluate the association between serum vitamin D level at hospital admission and the incidence of thrombotic events. Several other clinical outcomes (intensive care unit (ICU) admission, mechanical ventilation, and mortality) were also analyzed. RESULTS The mean vitamin D level at hospital admission was 26.7±13.0 ng/mL (N=208). Approximately one-third of patients had vitamin D deficiency (n=68, 32.7%). No relationship was found between vitamin D deficiency and the occurrence of thrombotic events. The incidence of PE was 19.1% in vitamin D deficient patients and 11.4% in vitamin D sufficient patients (p=0.13). The incidence of DVT was 8.6% in vitamin D deficient patients and 9.6% in vitamin D sufficient patients (p=0.46). After adjusting for confounders, vitamin D deficiency was positively correlated with admission to the ICU (OR 3.047, 95% CI 1.57-5.91, p=0.001) and overall mortality (OR 3.76, 95% CI 1.29-11.01, p=0.016). Vitamin D deficiency was not associated with the need for mechanical ventilation. CONCLUSIONS This study found no significant associations between vitamin D deficiency and thrombotic events or the need for mechanical ventilation in hospitalized SARS-CoV-2 patients. Patients with vitamin D deficiency were more likely to be admitted to the ICU and had increased overall mortality. This abstract is funded by: USF Health Morsani College of Medicine Am J Respir Crit Care Med 2022;205:A4571 Internet address: www.atsjournals.org Online Abstracts Issue