Abstract: Acta Biomed 2023; Vol. 94, N. 1: e2023007 DOI: 10.23750/abm.v94i1.13655 © Mattioli 1885 Or iginal inve stigations/commentar ie s Baseline serum vitamin A and vitamin C levels and their association with disease severity in COVID-19 patients Gulseren Yilmaz1, Huri Bulut 2, Derya Ozden Omaygenc 3, Aysu Akca4, Esra Can4, Nevin Tuten4, Aysegul Bestel 4, Baki Erdem5, Uygar Ozan Atmaca1, Yasin Kara6, Ebru Kaya1, Murat Ünsel 7, Ayca Sultan Sahin1, Ziya Salihoglu8 1 Kanuni Sultan Suleyman Training & Research Hospital, Department of Anesthesiology and Critical Care, ­ Istanbul, ­ urkey; 2Istinye University, Faculty of Medicine, Department of Biochemistry, Istanbul, Turkey; 3Istanbul Haseki T ­Training & ­Research Hospital, Department of Anesthesiology and Critical Care, Istanbul, Turkey; 4Kanuni Sultan Suleyman ­Training & ­Research Hospital, Department of Obstetrics and Gynecology, Istanbul, Turkey; 5Acıbadem University, Faculty of Medicine, Department of Gynecologic Oncology, Istanbul, Turkey; 6Kanuni Sultan Suleyman Training & Research Hospital, Department of General Surgery, Istanbul, Turkey; 7Basaksehir Cam ve Sakura City Hospital, Department of Anesthesiology and Critical Care, Istanbul, Turkey; 8Istanbul University – Cerrahpasa, Faculty of Medicine, Department of Anesthesiology, Istanbul, Turkey Abstract. Aim: We aimed to investigate the association between the serum concentrations of Vitamin A and Vitamin C and the severity of the COVID-19. Methods: Fifty-three consecutive PCR (+) COVID-19 patients admitted to a dedicated ward were enrolled in this study. Blood samples for serum Vitamin A and C measurements were drawn from all participants upon admission. All subjects underwent thoracic CT imaging prior to hospitalization. CT severity score (CT-SS) was then calculated for determining the extent of pulmonary involvement. A group of healthy volunteers, in whom COVID-19 was ruled out, were assigned to the control group (n=26). These groups were compared by demographic features and serum vitamin A and C levels. The relationship between serum concentrations of these vitamins and pre-defined outcome measures, CT-SS and length of hospitalization (LOH), was also assessed. Results: In COVID-19 patients, serum ­Vitamin A (ng/ml, 494±96 vs. 698±93; p<0.001) and Vitamin C (ng/ml, 2961 [1991-31718] vs. 3953 [1385-8779]; p=0.007) levels were significantly lower with respect to healthy controls. According to the results of correlation analyses, there was a significant negative association between Vitamin A level and outcome measures (LOH, r=-0.293; p=0.009 and CT-SS, r=-0.289; p=0.010). The negative correlations between ­Vitamin C level and those measures were even more prominent (LOH, r=-0.478; p<0.001 and CT-SS, r=-0.734: p<0.001). Conclusion: COVID-19 patients had lower baseline serum Vitamin A and Vitamin C levels as compared to healthy controls. In subjects with COVID-19, Vitamin A and Vitamin C levels were negatively correlated with CT-SS and LOH. (www.actabiomedica.it) Key words: Ascorbic acid, COVID-19, Hospital stay, Pulmonary disease, Vitamin A