COVID 19 is an ongoing global health challenge and deadliest epidemic coronavirus update. Early sequencing from the viral genome and knowledge from past coronavirus outbreaks has led to rapid advancements in the knowledge of how the virus spreads and infects humans. Evidence supporting potential beneficial roles of key essential nutrients vitamin C, Vitamin D3, Zinc, and B3 Vitamins is reviewed here in this article underlying the MOA (Mechanism of Action), preclinical studies and human intervention has led to the clinical trials of COVID 19. The prevalence of comorbidities in patients who are severely affected with COVID 19 has led some to suggest inflammation and altered immunity that contribute to the disease course in an individual. This has resulted in considerable scientific support for supplementation being potent immunomodulators may help in improving the defensive status of the individual.
Vitamin C helps in decreasing the severity of the contracting common cold. So supplementing with 200mg or more of vitamin C does not reduce the risk of contracting cold but it reduces the risk of severity and duration of the common cold. One study revealed that boluses of vitamin C given by intravenous infusion to COVID-19 patients, with repeated boluses if the condition was critical, improved the oxygenation status. All patients under treatment were discharged to home.
Vitamin D plays an important role in immune function. Classically known to promote bone health, Vitamin D enhances the innate immune system by stimulating the production of antimicrobial peptides, including cathelicidins and defensins, which target the large scope of pathogens. Another line of defense, Vitamin D helps maintain tight junctions, gap junctions, and adherens junctions as physical cellular barriers against pathogens. The data suggested that the effect of Vitamin D on SARS-CoV-2 infection will help in dampening the inflammatory response and cytokine storm
Zinc is involved in innate and adaptive immune responses, from immune cell development onwards, through mucosal integrity. Supplementation with zinc has been found to reduce respiratory infections in children and to cut short colds by a day. Studies are ongoing to test the effects of zinc supplementation in COVID-19.
Vitamin B3 is necessary as the primary source for NAD+ synthesis which is important in case of defective metabolism requiring a high demand of NAD+ especially seen in SARS CoV-2 infected patients at cellular levels. There may be NAD+ depletion and the intracellular immune system may be compromised. If there is not enough NAD+ for the cells to use, it may lead to viral replication.