ABSTRACT
Since the start of the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome-associated coronavirus-2, concerns about immunity and boosting the immune system have increased the demand for nutritional supplementation. Supplementation with vitamins C and D, zinc, quercetin, and melatonin has been found to be beneficial against infectious diseases by regulating the immune system. Adequate intake of these nutrients is particularly important for elderly patients, who are more vulnerable to the deleterious effects of COVID-19. Increased supplementation with these nutrients during COVID-19 infection may be advantageous, but toxicity should be addressed in order to ensure patient safety. Additional clinical trials should be conducted to further assess the potential of nutritional supplementation as a readily accessible and affordable treatment specifically for COVID-19.