Abstract: Redox Report Communications in Free Radical Research ISSN: (Print) (Online) Journal homepage: https://www.tandfonline.com/loi/yrer20 Vitamin D levels and oxidative stress markers in patients hospitalized with COVID-19 Emilija Atanasovska, Marija Petrusevska, Dragica Zendelovska, Katerina Spasovska, Milena Stevanovikj, Katerina Kasapinova, Kalina Gjorgjievska & Nikola Labachevski To cite this article: Emilija Atanasovska, Marija Petrusevska, Dragica Zendelovska, Katerina Spasovska, Milena Stevanovikj, Katerina Kasapinova, Kalina Gjorgjievska & Nikola Labachevski (2021) Vitamin D levels and oxidative stress markers in patients hospitalized with COVID-19, Redox Report, 26:1, 184-189, DOI: 10.1080/13510002.2021.1999126 To link to this article: https://doi.org/10.1080/13510002.2021.1999126 © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group Published online: 02 Nov 2021. Submit your article to this journal View related articles View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=yrer20 REDOX REPORT 2021, VOL. 26, NO. 1, 184–189 https://doi.org/10.1080/13510002.2021.1999126 RESEARCH ARTICLE Vitamin D levels and oxidative stress markers in patients hospitalized with COVID-19 Emilija Atanasovska a*, Marija Petrusevska a*, Dragica Zendelovska a*, Katerina Spasovska Milena Stevanovikjb, Katerina Kasapinovac, Kalina Gjorgjievska a and Nikola Labachevskia b , a Faculty of Medicine, University of Ss Cyril and Methodius, Institute of Preclinical and Clinical Pharmacology and Toxicology, Skopje, Republic of North Macedonia; bIntensive Care Unit, University Clinic for Infectious Diseases and Febrile Conditions, Skopje, Republic of North Macedonia; c Intensive Care Unit, University Surgery Clinic ‘St.Naum Ohridski’, Skopje, Republic of North Macedonia ABSTRACT KEYWORDS Background: COVID-19 is characterized by the presence of oxidative stress. Vitamin D status has been reviewed as one of the factors that may affect disease severity. The aim of this study was to assess the relationship between serum vitamin D levels, oxidative stress markers and disease severity in hospitalized COVID-19 patients. Methods: Vitamin D levels were measured in 33 patients with COVID-19. The total antioxidant power and plasma peroxides were determined in serum. Results: Severe COVID-19 patients have lower vitamin D levels (18.39 ± 2.29 ng/mL vs. 28.47 ± 3.05 ng/mL, p < .05) and higher oxidative stress compared to the moderate group. When divided according to serum vitamin D levels, significantly higher values of LDH (604.8 ± 76.98 IU/mL vs. 261.57 ± 47.33 IU/mL) and D-dimer (5978 ± 2028ng/mL vs. 977.7 ± 172 ng/mL) were obtained in the group with vitamin D below 30 ng/mL, followed with significantly higher levels of plasma peroxides (d-ROMs: 414.9 ± 15.82 U.Carr vs. 352.4 ± 18.77 U.Carr; p < .05) and oxidative stress index (OSI: 92.25 ± 6.60 vs. 51.89 ± 6.45; p < .001). Conclusion: The presented data provide a justification to consider vitamin D as an important factor that could ameliorate disease severity through its anti-inflammatory and antioxidant effects. COVID-19; vitamin D; oxidative stress; plasma peroxides; disease severity; antioxidants; inflammation