Vitamin C (also known as ascorbic acid, the pure form of vitamin C) is a natural antioxidant . Most animals make vitamin C but humans have lost this ability 1.
Therefore, humans typically get vitamin C from diet and/or vitamin supplements. In the skin, vitamin C is the predominant antioxidant, where the majority of the vitamin C is concentrated in the epidermis rather than in the dermis. Since the epidermis composes the outermost 10% of the skin and acts as the initial barrier to oxidant assault, it makes sense that it contains the highest levels of antioxidants of the skin (such as Vitamin C and E) 2.
When topically applied, vitamin C has been shown to display antioxidant and photo-protective properties 3.
- Nishikimi M, Fukuyama R, Minoshima S, Shimizu N, Yagi K. Cloning and chromosomal mapping of the human nonfunctional gene for L-gulono-gamma-lactone oxidase, the enzyme for L-ascorbic acid biosynthesis missing in man. J Biol Chem. 1994; 269: 13685-8
- Shindo Y, Witt E, Han D, Epstein W, Packer L. Enzymic and non-enzymic antioxidants in epidermis and dermis of human skin. J Invest Dermatol. 1994; 102:122-4
- Boyera N, Galey I, Bernard BA. Effect of vitamin C and its derivatives on collagen synthesis and cross-linking by normal human fibroblasts. Int J Cosmet Sci. 1998; 20:151–158