Covid: Best Foods and Vitamins to Boost Immune System Vitamin C, Vitamin D and Zinc may help. Choose foods rich in these vitamins.Tips by Doc Willie Ong (Internist and Cardiologist) #19 BOOSTcoviddocFOODSIMMUNEimmune systemIMMUNITYSYSTEMvideoVITAMINvitamin immunityVITAMINSvlogWillieYouTube