Vitamin C ( L-ascorbic acid ) is an essential nutrient that can only come from the healthy fruits and vegetables that contain it. Vitamin C is usually touted for its cold-fighting power, but it’s also under study for its impact on preventing and reversing aging skin. It works in two ways: as an anti-oxidant, as well as a booster of collagen formation – both of which are important to preserving and maintaining skin’s youthful appearance. The irony is that boosting your intake of Vitamin C-rich foods does not appear to impact your skin to any measurable degree, so cosmetic companies are hard at work to study whether it can be absorbed through the skin directly via topical creams and lotions. The other challenge is to keep the Vitamin C stable through production, transportation and exposure to air and light. Preliminary studies are promising, but in the meantime, you’ll probably get better results from limiting your exposure to the sun and using a combination of other products with proven anti-aging results.