While no vitamin can return your skin to its babyhood, there is evidence that some can help protect it from or reverse its sun damage.
One of the B-complex vitamins, B3, may fit the bill. The B vitamins convert pasta into energy and put fats and protein to work. They keep your skin, eyes, liver and nervous system in good shape. B3 in particular, also known as niacin, is involved in blood circulation and hormone production, too.
Apparently it likes to keep busy, because niacin has been shown to diminish dark spots and increase collagen production [source: AAD]. Collagen is a protein that helps make up the structure of the skin. When it breaks down, due to damage or age, wrinkles appear. UVA rays, since they penetrate so deeply into the skin, are very capable of destroying those fibers. It's possible to inject collagen to replace it, but the effect doesn't last long. Stimulating the skin to produce more of its own, on the other hand, would make a lasting difference.
Vitamin A -- the vitamin with the best claim to success on this page -- is a hero to photoaged skin. It's absorbed in the form of carotenoids or retinol, depending on whether you got it from an animal or a plant. Without vitamin A, you would go blind, and your body wouldn't be able to stave off infection. In addition to taking care of your vision and immune system, vitamin A helps out with cell differentiation and bone growth.
And topical retinoids -- a form of retinol that can be applied to the skin -- are clinically proven to treat wrinkles, hyperpigmentation and rough skin. The U.S. Food and Drug Administration has approved concentrations of two types of topical retinoids for that very purpose: tretinoin cream and tazarotene cream. Carotenoids haven't been shown to combat photoaging, but it's possible they can protect skin before the damage happens [source: AAD].
Next on our list: vitamin C, guardian of all bodily tissues. It heals your cuts, fixes up your bones, and maintains your teeth. It's also responsible for making your skin, ligaments and blood vessels -- by playing a role in the production of collagen.
It's also an antioxidant, that magical compound that we think fights the signs of aging as well as conditions from cancer to arthritis. Because of this quality and its role in producing collagen, it's possible that vitamin C could be very valuable in smoothing out wrinkles, but there just isn't enough evidence yet to make the call for sure.
But there's a caveat here: There aren't many clinically controlled studies using skin care products with these vitamins. While vitamin C in one form may prove effective on skin in a lab, that doesn't mean that any product containing it has the same benefits. There are lots of other ingredients that could block its effects, or it may not be the right derivative. So be a smart consumer. If it sounds too good to be true, it usually is.