By "it" what are you referring to? Vitamin D may have modulatory effects on the biochemical pathways linked in the original article. Most pharmaceutical produc

By "it" what are you referring to? Vitamin D may have modulatory effects on the biochemical pathways linked in the original article. Most pharmaceutical products we study aren't going to directly kill bacteria or viruses, usually they have a particular physical effect on a specific molecule that then leads, through various cellular pathways, to the death or suppression of the pathogen. I highly doubt Vitamin D directly kills anything, it could modulate symptoms or the pathophysiology of COVID-19 the disease, vs. SARS-COV-2 the virus itself. If "it" means UV light, yes there are UV sterilizers aplenty today. If "it" means outdoors/fresh air, there are a lot of components to that and it's not like "fresh air" enters "in vivo" per se.