Vitamin C and D Supplements to Prevent the Risk of COVID-19

Background: A virus is a tiny agent, around one-hundredth the size of a bacterium which can infect cells of plants and animals. Seven coronaviruses are known to infect humans; three of them are serious, namely, SARS (severe acute respiratory syndrome, China, 2002), MERS (Middle East respiratory syndrome, Saudi Arabia, 2012), and SARS-CoV-2 (COVID-19) (2019-2020). SARS-CoV and MERS-CoV belong to beta coronaviruses (betaCoVs). Objective: In this mini-review, we want to consider the importance of vitamin D and C, especially plants containing these two vitamins, in the fight against COVID-19. Methods: The manuscript includes review articles, randomized control experiments, analytical studies, and observations, which have been gathered from different sources such as Google Scholar, Scopus, Science Direct, and PubMed. A literature review was carried out using keywords such as vitamin D, vitamin C, COVID-19, influenza, plant, and coronaviruses. Results: Various sources of vitamin D for humans are food, dietary supplements, and the skin by exposure to 7-dehydrocholesterol to ultraviolet light. There are some new findings on the influence of vitamin D in preventing and controlling influenza and COVID-19. Vitamin D may play a role in preventing influenza and COVID-19 by producing large quantities of IL-1 and IL-6 or interleukins. Conclusion: Vitamin D deficiency is a potential link between respiratory infection and immune evasion, and vitamin D is a pleiotropic factor known to modulate the immune response against the pathogen.