Vitamin C is called a "universal ingredient" in skincare. Why is it found in so many products? The answer lies in its three scientifically proven effects.
Effect 1: Antioxidant -- protecting skin from free radicals
Reactive oxygen species (free radicals) generated by UV rays and stress oxidize cells, causing dark spots, wrinkles, and sagging. Vitamin C (L-ascorbic acid) neutralizes free radicals by being oxidized itself. While getting vitamin C from foods like lemons (~20mg per lemon) is important, topical application can achieve 20x higher local concentrations according to research.
Effect 2: Collagen synthesis -- the source of firmness and elasticity
Collagen is the protein that supports skin firmness, and vitamin C is essential for its synthesis. Specifically, it acts as a cofactor for the enzyme that hydroxylates proline, an amino acid in collagen. The importance of vitamin C is evident from scurvy -- a disease caused by the inability to produce collagen when vitamin C is deficient.
Effect 3: Brightening -- suppressing melanin production
Melanin, which causes dark spots, is produced by an enzyme called tyrosinase. Vitamin C inhibits this enzyme, suppressing melanin production. Furthermore, it can reduce already-oxidized dark melanin back to a lighter state. This is a unique characteristic of vitamin C not found in other brightening ingredients.
Understanding through food comparisons
Eating vitamin C-rich foods like lemons, strawberries, and bell peppers is great for health. However, orally consumed vitamin C is distributed throughout the body, so very little reaches the skin. That's why delivering it directly to the skin through skincare matters. In the next level, we'll explore the different ways to deliver it.
References
Key peer-reviewed sources behind the scientific statements in this article.
- Pinnell SR, Yang H, Omar M, Monteiro-Riviere N, DeBuys HV, Walker LC, Wang Y, Levine M. Topical L-ascorbic acid: percutaneous absorption studies. Dermatol Surg. 2001;27(2):137-142. PubMed
- Murad S, Grove D, Lindberg KA, Reynolds G, Sivarajah A, Pinnell SR. Regulation of collagen synthesis by ascorbic acid. Proc Natl Acad Sci U S A. 1981;78(5):2879-2882. PubMed
- Telang PS. Vitamin C in dermatology. Indian Dermatol Online J. 2013;4(2):143-146. PubMed