There is of course no data at all looking at vitamin C and coronavirus. That said am currently taking 1g a day because the potential downsides are so negligible.
just dont go over the top wit 5-8g
and also dont have 2litres of OJ as a alternative method of 1g of vitC
2litres of OJ also has 2 days worth of sugars. so then having other food and drink is a sugar overload