Spotlight on… vitamin A

It’s the skincare industry’s wonder ingredient for anti-ageing, but why does vitamin A have such a stellar reputation? Amanda Pauley gives the lowdown on everything you need to know

Why the hype?

Vitamin A is known as the gold standard in skincare for treating the signs of ageing, and for good reason. “It is second to none when it comes to improving the signs of photoageing. It is able to stimulate cellular turnover, pushing fresh cells to the surface for a youthful looking complexion, and this helps to unclog pores,” explains Daniel Isaacs, director of research at skincare brand Medik8.

It also enhances collagen production, which targets fine lines and wrinkles and helps block the formation of pigment for more even-toned skin, he adds.

It’s recommended that you start clients off on the lowest percentage of vitamin A, and then build them up slowly. As the skin acclimatises, it will be able to tolerate higher amounts. The pros suggest introducing it twice a week in the evening for the first two weeks, and then every other evening for the next two. After that, clients can move on to nightly application.

How does it work?

Although there are many forms of vitamin A, it’s important to understand the conversion process that all molecules of vitamin A undergo in order to be used on the skin.

“The only form that makes any direct changes to skin is retinoic acid, which acts on the cellular DNA through various receptors,” says Dr Gabriell Prinsloo, medical director for the International Institute of Anti-Ageing (IIAA). “All forms of vitamin A undergo a conversion process that transforms them into retinoic acid, which is used by the skin.”

The natural conversion pathway for vitamin A in skin is retinyl palmitate to retinol, to retinal, and finally to retinoic acid, she explains. “All forms are converted to be stored as retinyl esters when they are applied to the skin, and they all undergo the same process to convert them to retinoic acid.”

‘All forms of vitamin A undergo a conversion process that transforms them into retinoic acid, which is used by the skin’

What’s the retinoid effect?

If non-acclimatised skin is exposed to high levels of vitamin A, then the complexion can react negatively, known as the ‘retinoid effect’ – dryness, flakiness, redness, inflammation, puffiness and itchy red spots are common signs.

What are the different forms?

■ Retinol is the most well-known and popular form of vitamin A. When applied to the skin, it converts to retinaldehyde and then to retinoic acid.

■ Retinoic acid is the metabolically active form, which works on the DNA of the cell nucleus. “It is only available on prescription for topical use and is the most irritating,” explains Dr Prinsloo.

■ Retinaldehyde is typically used because it “is one step closer to the bioavailable form of vitamin A – retinoic acid,” advises Isaacs, adding that it must undergo only one conversion to become active.

‘As the weights of various forms of vitamin A  are so different, scientists have had to work out a way to give them an equivalent value’ 

■ Retinyl esters, such as acetate and palmitate, are some of the most stable storage forms of vitamin A and easier for the skin to tolerate.

■ Retinyl retinoate is an ester of all-trans retinoic acid and all-trans retinol. “It has direct activity on our skin cells, requiring no conversion steps like its cousins retinol and retinal,” says Isaacs.

Is percentage the key factor?

It is believed that the key factor when choosing vitamin A products for clients is percentage, but Clare Muir, director of education at IIAA, says it needs greater consideration. While percentages on vitamin A products are equal, the strengths may not be, she notes. “This is why, based on scientific research, it is more accurate to talk about vitamin A in IU (international units) or RE (retinol equivalents) instead of percentages. As the weights of various forms of vitamin A are so different, scientists have had to work out a way to give them an equivalent value.

“Various manufacturers make vitamin A in different strengths to be used in skincare products, so one version may have, for example, one million IU, and another 500,000 IU – which means that the first version at 1% will have double the strength of the second version at 1%.”