A recent study demonstrated that vitamin C was able to prevent genetic mutations in the skin due to oxidative damage. It is also an essential cofactor in collagen production so it can help to reduce wrinkle formation and protect the integrity of the skin. In Southern California we get a lot of oxidative damage from the sun, pollution, etc. and vitamin C should be a part of everyone’s daily regimen. Of course natural sources of vitamin C are preferable: oranges, kiwi, etc., however, this is one area where supplementation is also very useful.
 
Free Radic Biol Med. 2009 Jan 1;46(1):78-87. Epub 2008 Oct 9