“Vitamin C is not an antioxidant, but it contains amino acids.”

This statement was from a saleswoman who was trying to explain the differences between vitamin E and vitamin C skin-care products. Her comment is nothing less than silly. Vitamin C in any form is not an amino acid. There are only 20 amino acids, all protein-building substances, of which 10 are called “essential” for humans to consume in their diets, since the body cannot manufacture them on its own (Source: Oxford Dictionary of Chemistry, Third Edition, 1996, pages 30–32). In its natural form, vitamin C is ascorbic acid, and is most definitely and notably an antioxidant, not a protein (Sources: Advances in Experimental Medicine and Biology, 2002, number 505, pages 113–122; and Journal of Investigative Dermatology, February 2002, pages 372–379). Vitamin C is a worthy ingredient to look for in leave-on skin-care products such as moisturizers and toners because, when used in its stable form (watch for ingredients like magnesium ascorbyl phosphate and tetrahexyldecyl ascorbate), it can reduce the effects of free-radical damage (Source: Journal of the American Academy of Dermatology, June 2003, pages 866–874). I suspect the saleswoman I spoke with may have been confusing ascorbic acid with aspartic acid, which is a nonessential amino acid.