Vitamin A is often found in skincare products in its various forms to address photoageing of the skin.
Cosmeceutical preparations tend to use retinol, which is gentler and less irritant, whereas prescription strength creams/gels use tretinoin/retinoic acid, which is more effective but can be harsher on sensitive skin. Makers of the non-prescription creams and gels don’t have to say how much retinol their products contain, and in the short term, the products might not be as effective as tretinoin.
Cosmeceutical vitamin A preparations will however smooth out the skin and minimise the effects of sun damage, although generally, it can take about 3 to 6 months of daily use to notice a difference. With prescription retinoids, a patient might notice smoother, more even-toned skin in as early as 6 to 8 weeks. Before recommending a particular vitamin A preparation, we always take a full skin history and examine the skin to determine which would be most appropriate for an individual patient.
What is photoageing?
Photoageing is a term used to describe the visible changes in skin that we see over time due to a cumulative lifelong exposure to UV radiation, specifically to UVA.
The uppermost layer of the skin (stratum corneum) becomes thicker, giving the skin a dull, rough texture. The pigment in the skin becomes abnormally distributed, leading to freckles and “liver spots”. Wrinkles start to appear in the skin, initially under the eyes and on the cheeks, and pores become visibly more noticeable. As photoageing progresses, the wrinkles become more marked and the skin develops a thick leathery appearance, often with a yellowish tint. In some patients, the skin can develop a pebbly texture with scattered open comedones (blocked pores).
How does vitamin A affect photoageing?
Retinoids work in a number of ways to reduce and reverse the clinical signs of photoageing. They prompt surface skin cells to turn over and die rapidly, making way for new cell growth underneath. They hamper the breakdown of collagen and thicken the deeper layer of skin where wrinkles get their start. Retinoids will not thin the skin – they typically cause peeling and redness in the first few weeks of use, but they actually thicken the skin. For brown spots that give the skin an uneven tone, retinoids slough them off and curb the production of melanin, a darker pigment.
Clinical Action of vitamin A (retinoids) – what happens within the skin
Visible Effect of vitamin A (retinoids) – what improvement is seen
|Thins and compacts the stratum corneum||Smoother, softer skin texture|
|Thickens the epidermis||Tightening of the skin|
|Reverses keratinocyte atypia (skin cells containing abnormal DNA from repeated UV damage)||Improves or eradicates actinic keratoses (“sunspots”)|
|Disperses melanin throughout the epidermis||Improves blotchy hyperpigmentation|
|Stimulates dermal collagen deposition||Increases dermal volume and tightens the skin|
|Increases glycosaminoglycan (GAG) deposition||Increases dermal hydration and tightens the skin|
|Increases neovascularization (growth of new blood vessels) in the dermis||Gives a pinker rosy hue to the skin|
Preventing further damage
When using any active vitamin A product, it is important to stop, or reduce, ongoing photoageing. It makes little sense to improve the quality of the skin and then subject it to further damage from chronic ultraviolet (UV) light exposure.
Complete avoidance of sunlight for several years can actually reverse some histological signs of photoageing as the skin has the ability to repair itself if it is protected from continual photodamage.
In Australia total sun avoidance is difficult if not impossible for most people. Therefore we must settle for the next best thing – sun protection. The concept of sun protection encompasses sun protective clothing (including hats) and sunscreens.
The easiest to use and most reasonable protection for most people is sunscreen. Sunscreen should be worn every day, whether the person is outdoors a little or a lot. Because UV damage is cumulative in its effects, the prevention of even small daily amounts of sun damage over a long period of time can have a profound impact on the total amount of UV-induced damage.