You’re referring to supplements, which I didn’t cite exclusively. A lot of supplements are bunk because they offer the vitamin in its most basic form without other ingredients that act as a means for absorption. They never even make it into your bodies vital systems where they’re most needed. You literally just shit them out with whatever other garbage you ate that day. There are good supplements out there though that contain nutrients which aid in absorption. The best way to get vitamins though is through natural foods that contain them, hands down. Your body already knows how to use fruits, vegetables, and proteins and get the most out of them. Nature figured that shit out a long time ago.
If everyone who was affected by coronavirus had adequate vitamin intake, hell even just vitamin A alone, there would be less deaths and more mild cases. Vitamin A fortifies cell walls and makes it much more difficult for viruses to penetrate, especially in complex tissues like lung tissue, where most corona virus fatalities occur through pneumonia. The elderly are notoriously vitamin A deficient, the reasons for which are not fully understood, but it is well documented. I think we all know the statistics concerning age-related coronavirus deaths.
And that’s not even mentioning other essential nutrients that increase T cell production and the production of other white blood cells which battle viruses and other antigens.
It matters big time.