Vitamin C and Skin

Vitamin C, also known as ascorbid acid, is a vitamin found in many fruits and vegetables. It can also be used topically to treat things like hyperpigmentation (dark flat spots often caused by acne or other conditions like melasma) and photoaging. In this post I will break down what is actually known about topical Vitamin C and what questions about topical vitamin C still remain to be answered.

Topical Vitamin C is the most abundant antioxidant in human skin. It does several things in the skin, but probably the two most important relate to regenerating the anti-oxidant properties of Vitamin E and to getting rid of free radicals, which are created when the sun's radiation hits the skin. In addition to these things, Vitamin C is involved in a lot of other processes involved in making blood vessels and collagen, but I am just going to focus on the skin today.

Regular Vitamin C, is absorbed best when (no surprise here) it is in a very acidic form. A pH of 3.5 (in between vinegar and stomach acid, roughly), has been shown to absorb best into skin. As you can imagine, rubbing an acid on your face can be irritating so many people have developed "cousins" of Vitamin C that are more stable at a neutral pH (7), but still have the same ability to scavenge the free radicals produced by the sun.

So that's a little bit about the science behind Vitamin C. But does that science translate into improved skin? The answer is probably yes. In one (small) clinical trial of topical Vitamin C (the regular kind, not one of the fancy substitutes), where patients got the Vitamin C on half their face but just the vehicle (all the ingredients of the cream without the Vitamin C) on the other side, the side with the Vitamin C had significant improvement in photoaging (sun damage) after 3 months of use.

Vitamin C has been suggested to have other uses as well, including as a lightening agent for dark spots either caused by melasma (a "browning" of the skin often occuring in pregnancy or on oral contraception) or inflammation such as acne.

Vitamin C has also been shown to work as a sunscreen. It seems to work better at blocking UVA (more the cause of photoaging than skin cancer), and Vitamin E seems to work better at blocking UVB (more the cause of skin cancer than photoaging).

All these good things Vitamin C reportedly does need to be taken with a grain of salt. In reality we know far less about what topical Vitamin C does than we do about what most prescription treatments do to the skin. The clinical trials have been small and some of them have been done better than others. The laboratory data seem promising, but they often do not translate to the clinical setting. Stay tuned for more as the science of Vitamin C becomes clearer.

For now, if topical Vitamin C is something you think you might want to add to your skin regimen there are a number of products available in various formulations. Obagi and NuFountain are two companies that make affordable Vitamin C preparations. You may want to start out with a 10% L-ascorbic acid formula. It that is too irritating step down to the 5%. If the 10% formula is a piece of cake for you then you can consider increasing to the 20% lines.

I hope you enjoyed. Please feel free to email me with any questions.