Why is Vitamin C Essential to Skincare?

Why is Vitamin C Essential to Skincare?

The antioxidant properties of vitamin C(ascorbic acid) and its role in collagen synthesis make vitamin C a vital molecule for skin health. Dietary and topical ascorbic acid have beneficial effects on skin cells, and some studies have shown that vitamin C may help prevent and treat ultraviolet (UV)-induced photodamage. Aging, however, causes a decline in vitamin C content in both the epidermis and dermis. Excessive exposures to UV light or pollutants may also lower vitamin C content.

Vitamin C can be provided to the skin through topical application. The stratum corneum is the primary obstacle to efficient vitamin C absorption from external sources; removal of the stratum corneum by laser, chemical, or mechanical methods enhances absorption. Although similar studies are still required for humans, studies in laboratory animals show that percutaneous vitamin C absorption greatly depends on pH. Preparations with a pH below 4.0 aid in transport by promoting the uncharged form of vitamin C, ascorbic acid. Although concentrations of vitamin C up to 30% have been used for animal studies, maximal absorption was achieved with a 20% vitamin C solution, with higher concentrations showing lower absorption

Vitamin C limits the damage induced by ultraviolet (UV) light exposure. Vitamin C is not a “sunscreen” because it does not absorb light in the UVA or UVB spectrum. Rather, the antioxidant activity of vitamin C protects against UV-induced damage caused by free radicals

Topical application of vitamin C, alone or in combination with other compounds, may result in greater photoprotection than oral supplementation because of the more direct route of administration. In one mouse study, topical application of ascorbic acid delayed the effects of chronic high-dose UVB exposure on the skin, including a reduction in skin wrinkling and the development of skin tumors (13). In pig models, topical application of vitamin C reduced the number of sunburned cells, decreased erythema response, and reduced DNA damage induced by UVA exposure. Topically applied combinations of vitamin C and vitamin E are more effective in preventing photodamage than either vitamin alone. In particular, this combination of antioxidant vitamins decreased the immunosuppressive effects of UV exposure and decreased cell damage.

In cell culture models, vitamin C supplementation has many beneficial effects in combating photodamage. Specifically, vitamin C has been shown to stabilize collagen mRNA, thus increasing collagen protein synthesis for repair of the damaged skin.

Refereces: Skin and Health