the role of vitamins on the prevention and/or treatment of covid-19 infection; a systematic review

Background]vitamins had been reported repeatedly as important micronutrients, on immune system.[objectives]in this study roles of vitamins on immune system were discussed in detail, as well as their probable roles on the prevention/treatment of viral infections including covid19 infection.[method]totally, 57 articles had been extracted from common indexing databases/websites, which were then classified to different main groups and subgroups. the roles of vitamins on the prevention and/or treatment of covid19 infection had been also reviewed, and finally their contents had been purified and listed into different categorizations. moreover, differential percentages of each vitamin related studies, differential percentages of studies on the association with covid19, and mechanisms of the vitamins effects on immune system had been reviewed for each vitamin.[results]in this study, the reviewed articles had been categorized into 5 main vitamin groups and 7 subgroups for vitamin b family groups. the most studied vitamin group was identified to be the b vitamins group followed by the vitamins a, d, and e groups that were ranked in next steps, respectively. however, in individual comparison of vitamins, vitamin a had been identified as the vitamin with maximum number of studies. accordingly, more than half of these studies (66.66%) had focused on the immunemodulatory effects of vitamin d on the prevention and/or treatment of covid19 infection.[conclusions]briefly, this study showed that, among all vitamins, roles of vitamin a, c, d, and e are more defined and maybe more effective on immune system, which emphasizes on the importance of vitamins in prevention of several viral infections like covid19. therefore, sufficient vitamin intake can be recommended to prevent viral infections like covid19 infection.