The role of vitamin D on the risk of SARS-Cov-2/covid-19 part I: Narrative review

ABSTRACT

The objective of this review was to update the evidence on the role of vitamin D and its possible mechanisms of action on COVID-19. At present, multiple pleiotropic benefits associated with vitamin D have been suggested, among which a possible immunomodulatory effect with anti-inflammatory potential has been suggested on respiratory viral infections such as SARS-CoV-2, responsible for the COVID-19 pandemic. In this sense, current scientific evidence raises a possible association between vitamin D insufficiency (<30 ng/ml) and the risk of COVID-19 illness, in such a way that the most accepted recommendations by the scientific community suggests that supplementation not exceed the recommended dietary intake (600-800 IU/day) for healthy populations and between 400-2.000 IU/day for populations at risk of deficiency. On the other hand, scientific evidence does not recommend systematic supplementation> 4.000 IU/day, only supporting these recommendations in risk conditions in populations with confirmed insufficient levels. This review concludes that in the various countries, such as Chile, whose availability of foods rich in vitamin D is scarce should try to supply food to combat food insecurity and vitamin deficiencies related to the incidence of COVID-19. For countries whose sanitary measures prevent the population from having food that allows obtaining or maintaining sufficient levels (>30 ng/ml), supplementation between 400 and 2.000 IU/day of vitamin D is suggested. However, these associations are still controversial, more randomized clinical trials are needed to make clinical decisions.