COVID-19: The significance of platelets, mitochondria, vitamin D, serotonin and the gut microbiota

We provide a brief review of the significance of platelets, mitochondria, vitamin D, serotonin and the gutmicrobiome in COVID-19. We hypothesize that hyperactive platelets and mitochondrial dysfunction, as well as low vitamin D level, gut dysbiosis and increased serum serotonin produced by enterochromaffin cells, may all represent important aspects in the pathophysiology of COVID-19.