Photo damage (photo-aging) and chronologic aging result in the accumulation of oxidative damage to proteins, which can lead to changes in the structure of your skin. Not only does vitamin C have antioxidant functions, but it can also regulate the synthesis of the structural protein collagen. Vitamin C creates extracellular stability and supports the epidermis through its role in the hydroxylation of collagen.
As previously mentioned, the supplementation of vitamin C can aid in repairing photodamaged skin. It does so by stabilizing collagen mRNA, which increases collagen protein synthesis that repairs the damaged skin. At the same time, when there is photo damage, the elastin protein often becomes overproduced as a result and vitamin C supplementation will aid in decreasing the elastin production. As we age, fibroblasts reduce in capacity, but vitamin C will increase the production of them dramatically as well as encourage DNA repair within cultured fibroblasts.
Skin health studies are performed by assessing changes in depth, the amount of wrinkles or simply by the person's own perception of their skin. Higher intakes of vitamin C have been shown to improve skin appearance, including decreasing wrinkles. You can also achieve similar results by using vitamin C (3-10%) topically for at least 12 weeks. This also reduces roughness of the skin, reduces protein fiber damage and increases collagen production. Using a topical vitamin C supplementation can also reverse some age-related structural changes between the dermis and epidermis.