ABSTRACT
COVID-19 (COronaVIrus Disease of 2019), the disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), represents an ongoing global health challenge and the deadliest epidemic coronavirus outbreak to date. Early sequencing of the viral genome and knowledge from past coronavirus outbreaks (SARS-CoV-1 and Middle East Respiratory Syndrome, MERS) has led to rapid advances in knowledge of how the virus spreads and infects human hosts. Unfortunately, advancing knowledge has not yet produced a treatment that substantially lowers morbidity or mortality and only recently resulted in the development of a vaccine that prevents severe disease. Mounting evidence supports the notion that dietary supplementation of key essential nutrients may contribute to the body's defenses against infection as well as bolster the body's responses to infection. Evidence supporting the potential beneficial roles of vitamin C, vitamin D, zinc, and B3 vitamins is reviewed here, revealing a combination of basic research elucidating underlying mechanisms of action, preclinical studies and human intervention studies has led to the proliferation of registered clinical trials on COVID-19. Overall, the data suggest this collection of nutrients has a promising impact on reducing the risk and/or severity of COVID-19, although firm conclusions await the results of these trials.