Author: Vanessa Ngan, Staff Writer, 2002.
Topical vitamin C or ascorbic acid is a popular vitamin being added to skin care products. Currently, there are many advertising claims of a topical formulation containing antioxidants that will protect against and reverse ageing. However, the truth is that many of the available formulations contain very low concentrations of antioxidants that are not well absorbed by the skin. Vitamin C is an antioxidant, which when manufactured into a stable topical formulation, is proven to be effective in protecting against photoageing of the skin.
To understand how topical vitamin C works an understanding of the relationship between free radicals and antioxidants in the body is necessary.
Topical vitamin C has shown to protect the skin from UV damage caused by prolonged sun exposure by reducing the amount of free radical formation and sunburn cells. Exposure to UV light has also shown to decrease the naturally occurring vitamin C levels in the skin. Thus the topical application of vitamin C restores these photoprotectant levels. Other studies also suggest that vitamin C may play a part in the collagen biosynthetic pathway by activating collagen metabolism and dermal synthesis of elastic fibres.
Studies have shown the following benefits of using topical vitamin C preparations.
Everyone will benefit from maintaining adequate vitamin C levels. For most people, this can be achieved by eating more than five servings of fruit, vegetables and juices daily. There are many topical vitamin C preparations available that claim to benefit photoaged skin. However, almost all of these claims have no rigorous scientific testing to back them.
A correctly formulated topical vitamin C preparation is a costly process. Many available formulations are ineffective. The problems lie in the fact that vitamin C is most commonly found in the form, L-ascorbic acid, which is highly unstable when exposed to oxygen, making it useless. Also, many of the currently available topical vitamin C preparations do not penetrate the skin sufficiently to make any difference. Research is underway to optimise a stable and effective topical vitamin C formulation.
The treatment and prevention of scurvy, which is due to dietary vitamin C deficiency, requires oral replacement of ascorbic acid.
© 2019 DermNet New Zealand Trust.
DermNet NZ does not provide an online consultation service. If you have any concerns with your skin or its treatment, see a dermatologist for advice.