Abstract: (2021) 21:899 Razeghi Jahromi et al. BMC Infect Dis https://doi.org/10.1186/s12879-021-06617-3 Open Access RESEARCH The correlation between serum selenium, zinc, and COVID‑19 severity: an observational study Soodeh Razeghi Jahromi1†, Hedieh Moradi Tabriz2†, Mansoureh Togha3,4* , Shadi Ariyanfar1,3, Zeinab Ghorbani5,6, Sima Naeeni4, Samaneh Haghighi3,4, Aboozar Jazayeri3, Mahnaz Montazeri7, Mohammad Talebpour8, Haleh Ashraf9,10, Mehdi Ebrahimi11, Azita Hekmatdoost1 and Elham Jafari3 Abstract Background: Without an adequate immune response, SARS-CoV2 virus can simply spread throughout the body of the host. Two of the well-known immunonutrients are selenium (Se) and zinc (Zn). Se and Zn deficiency might lead to inflammation, oxidative stress, and viral entry into the cells by decreasing ACE-2 expression; three factors that are proposed to be involved in COVID-19 pathogenesis. Thus, in the current study we aimed at evaluating the correlation between serum Se and Zn status and COVID-19 severity. Methods: Eighty-four COVID-19 patients were enrolled in this observational study. Patients were diagnosed based on an infectious disease specialist diagnosis, using WHO interim guidance and the recommendations of the Iranian National Committee of Covid-19. The patients with acute respiratory tract infection symptoms were checked for compatibility of chest computed tomography (CT) scan results with that of Covid-19 and Real-time polymerase chain reaction (RT-PCR) for corona virus infection. The severity of Covid-19 was categorized into three groups (mild, moderate, and severe) using CDC criteria. Serum Zn and Se level of all subjects was measured. The severity of the disease was determined only once at the onset of disease. Results: According to the results of linear regression test, there was a significant association between Zn and Se level and COVID-19 severity (β = − 0.28, P-value = 0.01 for Se; β = − 0.26, P-value = 0.02). However the significance disappeared after adjusting for confounding factors. Spearman correlation analysis showed a significant negative association between serum Zn, Se and CRP level (r = − 0.35, P-value = 0.001 for Se; r = − 0.41, P-value < 0.001 for Zn). Conclusion: Results suggest that increasing levels of Se and Zn were accompanied by a decrease in serum CRP level. However, the significant association between Se, Zn, and disease severity was lost after adjusting for confounding factors. Keywords: COVID-19, Zinc, Selenium, Nutritional status, Immunity *Correspondence: toghae@sina.tums.ac.ir † Soodeh Razeghi Jahromi and Hedieh moradi tabriz have contributed equally. 3 Headache Department, Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran Full list of author information is available at the end of the article