Vitamin C is ranked as one of the best anti-aging ingredients on the market and the key to maintaining a smooth, even, and glow complexion. Dietary intake may be high, however when applied topically, its going straight to the targeted skin area.
Vitamin C is an essential part of skin health both as a small molecular weight antioxidant and as a critical factor for collagen synthesis. Vitamin C contributes to photoprotection, decreases photodamage, and is needed for adequate wound healing. Oral supplementation with vitamin C may help prevent UV-induced damage, especially in combination with supplemental vitamin E. Dietary vitamin C may also provide photoprotection, but the extent of the protective effects will require additional research.
Topical application of vitamin C appears to be an effective route for delivering ascorbic acid to the skin because ascorbic acid appears to be taken up readily at an acidic ph. Despite inconsistencies in vitamin C preparations and study design, the data suggest that vitamin C is most effective in protecting against damage induced by UV light and has utility in the treatment of photodamage and/or skin wrinkling.
Although vitamin C appears to benefit dry skin and may support wound healing, further research is needed to determine the effect of vitamin C on both. Lastly, the greatest effects of vitamin C supplementation are seen when it is combined with other micronutrients, such as vitamin E and zinc. [ Dr. Alexander J. Michels, Ph.D. ,Oregon State University, Sep 2011]