If I have it right then vitamin D is a regulator of many processes. Vitamin C might have more direct effects.
But then, I'm not at all sure I have it right.
We started taking 4k to 6k daily of D3 last year and have hardly had a sniffle. It is a wonder vitamin. Make sure you take D3 and the gelcaps not the tablets.
>> “If I have it right then vitamin D is a regulator of many processes.” <<
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Thus making it more of a hormone than a vitamin.