http://www.cure-guide.com/Articles_o..._for_kids.html1/2 teaspoon vitamin C powder (optional, equiv. to 1000 mg vitamin C)
It isn't crucial to really have a table. The reason why is Vitamin C is a water soluable vitamin. The body will use what it needs and any excess will be excreted in the urine. Most recommendations are if a child is sick you give vitamin C until you have reached bowell tolerance (can google vitamin c and bowell tolerance and you prolly will get a lot of links) then you back off a little on that dosage. Every body is different on bowell tolerance.
As to a preventative dosage, the above link is what that doctor recommends and he writes great books..check out his webpage and the child health guide