Abstract: 991246 research-article2021 SMO0010.1177/2050312121991246SAGE Open MedicineMuhammad et al. SAGE Open Medicine Original Research Article Deficiency of antioxidants and increased oxidative stress in COVID-19 patients: A cross-sectional comparative study in Jigawa, Northwestern Nigeria SAGE Open Medicine Volume 9: 1­–8 © The Author(s) 2021 Article reuse guidelines: sagepub.com/journals-permissions https://doi.org/10.1177/2050312121991246 DOI: 10.1177/2050312121991246 journals.sagepub.com/home/smo Yahaya Muhammad1 , Yamuna Aminu Kani2, Sani Iliya3 , Jafaru Bunza Muhammad4, Abubakar Binji5, Abdurrahman El-Fulaty Ahmad6 , Muhd Bashir Kabir7, Kabir Umar Bindawa6 and Armaya’u Yelwa Ahmed8 Abstract Introduction: The COVID-19 is a pandemic caused by SARS-CoV-2 which has infected over 74 million people, killing more than 1,600,000 million people around the world as of 17th December 2020. Accumulation of free radicals coupled by weakened antioxidant system leads to oxidative stress, which will further worsen respiratory diseases, COVID-19 inclusive. This study aimed to examine the levels of some antioxidants and oxidative stress markers in COVID-19 patients. Methods: This was a cross-sectional comparative study in which 50 COVID-19 symptomatic patients who were on admission at the COVID-19 isolation center in Jigawa, Northwestern Nigeria, were recruited. Twenty one (21) apparently healthy individuals were included as controls. Levels of antioxidant trace elements (Se, Zn, Mg, Cu and Cr), 8-isoprostaglandin F2 alpha and malondialdehyde in the plasma and erythrocytes activity of glutathione, glutathione peroxidase, superoxide dismutase and catalase were determined. Results: The plasma concentrations of vitamins A, C and E were significantly lower (p < 0.001) in COVID-19 patients than controls. Activities of glutathione, glutathione peroxidase, catalase and superoxide dismutase were lower in COVID-19 subjects than controls (p < 0.001). The concentrations of Se, Zn, Mg and Cu were significantly lower (p < 0.001; p = 0.039; p < 0.001; and p < 0.001), respectively, in COVID-19 patients than controls, while chromium showed no significant difference (p = 0.605). Oxidative stress marker, 8-isoprostaglandin F2 alpha, was significantly higher (p = 0.049), while malondialdehyde was lower (p < 0.001) in COVID-19 patients than controls. Conclusion: In conclusion, COVID-19 patients are prone to depleted levels of antioxidant substances due to their increase utilization in counterbalancing the negative effect of free radicals. Furthermore, COVID-19 infection with other comorbidities, such as malaria, hypertension and diabetes, are at higher risk of developing oxidative stress. Keywords COVID-19, antioxidants, free radicals, vitamin A, Nigeria Date received: 17 October 2020; accepted: 6 January 2021 1  epartment of Chemical Pathology, Rasheed Shekoni Teaching Hospital D Dutse, Dutse, Nigeria 2 College of Medicine and Health Sciences, Federal University Dutse, Dutse, Nigeria 3 Department of Biological Sciences, School of Pure and Applied Sciences, Mount Kenya University, Thika, Kenya 4 Department of Chemical Pathology, School of Medical Laboratory Sciences, Usmanu Danfodiyo University, Sokoto, Nigeria 5 Health Without Gaps (HWG) Foundation, Hopkins, MN, USA 6 Department of Medical Laboratory Science, Ahmadu Bello University Zaria, Zaria, Nigeria 7 Department of Biotechnology, Federal University Dutse, Jigawa, Nigeria Department of Chemical..