Vitamin C or ascorbic acid is one of the most researched skincare ingredients and probably one of the most common.
Ascorbic acid is a key antioxidant and a cofactor in at least eight vital enzymatic reactions. This vital vitamin destroys free radicals and plays a major role in the formation of collagen everywhere in the body, including the skin. Problem is, humans can’t produce vitamin C because we lack the enzyme which converts glucose into ascorbic acid. Almost all mammals are luckier than us in that respect being able to create vitamin out of sugar, but we don’t have this excuse for having a sweet tooth. At least getting a sufficient intake of vitamin with food is not very difficult, especially at a young age.
Normally, high contents of ascorbic acid are present in the dermis and epidermis. Ascorbic acid in the skin can be damaged or destroyed by environmental pollution agents, such as ozone, by smoking and by ultraviolet radiation. Sadly, the level of vitamin C also decreases with age for reasons yet unknown.
In the epidermis vitamin C levels drop 31% when the skin is damaged by the sun and 39% in mature skin. In the dermis, the levels of vitamin C are 37% lower in photo-damaged skin and 30% lower in ageing skin. Lower contents of ascorbic acid lead to wrinkles, loss of elasticity and other signs of ageing. Same happens with vitamin E.
If low level of vitamin C in the skin correlates with unwanted skin changes, then increasing it should bring about positive development, shouldn’t it? Vitamin C has been successfully applied in skin care since 1980s. The promised skin benefits are well known: wrinkle reduction, thicker epidermis, reduced UV damage, skin lightening and improvement in acne because of its ability to decrease squalene oxidation in the sebum. Vitamin C is one of the key ingredients of skin care during menopause.
Does this sound a little too good to be true? Well, there is another side of the coin: it is very difficult to deliver vitamin C to the skin in a stable, effective and non-irritating form.
Furthermore, the effect of vitamin C topical application varies widely from person to person, some users report all kinds of benefits from their vitamin C products, while others can’t detect any difference at all. Why is that? It has been discovered that people with high dietary intake of vitamin C experience very little or no effect from skincare with vitamin C. Taking vitamin C supplements or simply maintaining a healthy diet with plenty of vegetables and fruit brings the level of vitamin C in the skin up to the point where it can’t increase any more because of saturation.