Dermatologists have long recommended vitamin C for brighter and healthier skin. With a boost in the skin care industry, vitamin C serums generate billions in annual sales. But the growing body of literature suggests that reality is more complicated than marketing claims suggest.
Undoubtedly, vitamin C is essential for human skin. Studies have shown that normal skin contains high concentrations of the vitamin, with epidermal levels two to five times higher than in the dermis.
There are various roles associated with the compound, including serving as a cofactor for collagen synthesis, acting as an antioxidant against radicals formed by ultraviolet rays, suppressing melanin, and stimulating the formation of ceramides, the lipid molecules that bind skin cells together.
The real problem, however, is getting vitamin C into the skin.
Since it is a water-soluble and charged nutrient, it is most likely to be repelled by the surface of the skin. The beneficial penetration only occurs when formulations have a pH value below 4.
For better stability and penetrations, manufacturers usually use derivatives such as magnesium ascorbyl phosphate, ascorbyl glucoside and ascorbyl palmitate. However, they must be converted into active vitamin C once they are inside the skin.
Most of the serums never penetrate deep enough to work. Those who have only three things including:
- Pure vitamin C (L-ascorbic acid) at low pH
- Put in opaque airtight bottles to prevent oxidation
- Often combine vitamin C with vitamin E for better results.
However, if vitamin C levels are already saturated through diet or oral supplements, topical application may not increase skin levels further.
