This is a good plan, I used to do the same.I take 2-3 grams per day under normal conditions, and if I am feeling any kind of infection I double or triple that and add in liposomal vitamin C as well. I don't know of any firm guidelines, but my dosing is loosely based on what animals that produce their own vitamin c (almost all of them) produce.
I have switched to getting a fresh made green drink every morning for my vitamin and mineral needs. I think I do feel better and it is also a major boost to my nitric oxide levels! I think there is something to the video Gman posted.
I drink 8 ounces of OJ (90mg) every morning which is the recommended daily amount of vitamin C for an adult male.How much do you take ?