COVID-19(33) Trace element(26) Treatment(21) SARS-CoV-2(20) COVID-19 patient(16) Selenium(15) Effect(14) Result(13) serum(13) Patient(13) patients with COVID-19(13) association(11) immune system(11) addition(11) Inflammation(11) Zinc(10) biochemical(9) Concentration(9) Antiviral(9) objective(9) Infection(9) changes in(8) COVID-19 patients(8) disease(8) deficiency(8) evaluated(8) infected with COVID-19(8) iron(8) significant difference(8) analyzed(8)