Vitamin C (ascorbic acid) is a natural blood thinner, prevents blood clotting. Zinc helps building up mucosa, the "frontline" barrier of our immune system.
Vitamin D is quite complex, actually a pre-hormone (calciferol) mainly used for the processing and distribution of calcium, in combination with vitamin K2.
Always take Vit-K2 with Vit-D, because VD is raising blood calcium levels and K2 makes sure that it gets where it belongs to (bones, teeth) instead of soft tissues, where it can cause a lot of harm over longer times of use.
Some comments on vit regimens: if you take a large dose on any vitamin, especially water-soluble like vit C, other vitamins will be removed by kidney together with it, so at the minimum take some vit Bs with it.
1g of vit C/hour is a horse size dose anyway, but to each their own. For myself, 0.5g/once a day when i feel under weather is enough.
Interesting point reg vit K. It does help with bone metabolism, but it is also widely available in food (K1 in greens and K2 in meats, cheese and eggs) plus half of the daily requirement is being provided by the gut bacteria.
Since vit K is essential for blood clotting (which basically means helping survival), I found it interesting that we have a gut co-habitant (bacteria) that helps us to stay alive, which "benefits" them in turn.
It's funny how it all fits together.
Thanks for adding all the detail i lacked in my post (had to put a kid to sleep).
I'd like to add that K2 is also capable of removing (!) arterial plaque, which has been proven in a dutch study, which was a small one, but delivered clear results.
Seems like K2 generally helps to regulate clotting in body liquids.
A dose of 1g/h of pure vitamin C would make me shit my guts out after a few hours, btw.