Vitamines cannot be patented by pharmaceutical firms. So their supplements could be made by anyone. Also having vitamine D deficit makes you potential customer

Vitamines cannot be patented by pharmaceutical firms. So their supplements could be made by anyone. Also having vitamine D deficit makes you potential customer of all kind alternatives made by pharma because of your weak immunity. Agenda against vitamine D is strong and make me sceptical everytime I hear about danger of sun exposing or how vitamine D is not working.