Vitamin C (as ascorbic acid)
Vitamin C is a water-soluble vitamin that is naturally present in certain foods, that may be added to other meals, and that is also available for purchase as a nutritional supplement. Vitamin C can be found in all three of these forms. Because the bodies of humans are unable to generate vitamin C spontaneously, as is the case in the bodies of most other animals, it is very necessary to consume sufficient amounts of vitamin C through one's diet.
Resources: Vitamin C