Vitamin C is one of the most studied cosmetic ingredients. There is enough well established and independent research which shows that vitamin C really works. But what does it do exactly? We already know that vitamin C is an important part of our diet. Which is why in earlier times sailors who went without fruit and vegetables for long periods of time developed scurvy through lack of vitamin C. But it is also an important ingredient in cosmetic products.
Collagen production, and much more!
Vitamin C is essential for the formation of collagen (connective tissue). This collagen is required for strengthening the skin. If you add Vitamin C to fibroblasts in a test tube collagen production is drastically increased. It also stimulates the production of collagen when applied to human skin - (abstract).
Vitamin C can also reduce acne and pigment spots, and improve rosacea. In clinical tests it was revealed that the skin of volunteers became smoother and stronger after long-term use. There's more, vitamin C is also an anti-oxidant and can limit UV damage. So, all in all, vitamin C is almost a compulsory ingredient in your cosmetic product - (abstract/abstract/abstract).
There are some conditions
- Vitamin C is only effective in high concentrations (at least 4% is required). In order to find out if there is enough added to a product check the ingredients list: it should be listed at the top or at least be found in the top third of the ingredients list.
- Vitamin C is most effective when combined with other anti-oxidants. The combination of vitamin C (ascorbic acid) and vitamin E (tocopherol) is a golden double act -(abstract).
- Vitamin C is very unstable and so becomes less effective if it comes into contact with moisture, light and oxygen. Oxidized vitamin C (vitamin C that has reacted with oxygen in the air) is not only inactive but can also form oxygen radicals (the opposite effect). This is one reason not to put a vitamin C product in a pot or glass bottle.
Alternatives: vitamin C derivatives
A good alternative is to use vitamin C derivatives. These are substances where a particle is attached in order to make it more stable. These substances are less irritating but also have more difficulty penetrating through the skin. Unfortunately even the stable form of vitamin C has problems when exposed to oxygen. Therefore when buying a product with high concentrations of these ingredients its best to choose one with a pump. Examples of such vitamin C variants are:
- Sodium Ascorbyl phosphate
- Magnesium Ascorbyl phosphate
- Ascorbyl palmitate
As a nutricosmetic?
Just as Peter Velthuis wrote in my blog, vitamin C is an ingredient that has a positive effect on the skin if you take it orally. However, in this instance, your skin doesn't receive the necessary concentrations of ingredients required in order to achieve the aforementioned effects.
(Dr. Jetske Ultee-Research Physician Cosmetic Dermatology)