This is the first of a seven-part series, where we invite skin and beauty experts to explain the intricacies of the vitamins found in our skincare products

Vitamin A, retinoids, retinoic acid and retinol—what's the difference among all of them? While we often see these words listed in our beauty treatments and products, how exactly do they work and what are the risks of using them? We ask Dr Lam Bee Lan of Ageless Medical and Dr Toby Hui of Freia Medical to break down the jargon for us.

What is Vitamin A?

Vitamin A is a group of fat-soluble compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids. Best known for maintaining eye health and vision, the vitamin is also essential for growth and development, to support healthy skin cells, and to build a strong immune system.

Sources of vitamin A found in food include cod liver oil, eggs and beta-carotene-rich vegetables like carrots, broccoli and spinach.

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What does Vitamin A do for our skin?

According to Dr Lam Bee Lan, founder and director of Ageless Medical, topical application of vitamin A is the best way for our skin to reap its benefits, as the skin is the last organ to get the vitamins we consume.

“As a derivative of the vitamin A family, retinoids are a dermatological treatment for patients suffering from breakouts and are conventionally used in two familiar forms—retinoic acid and retinol,” she says.

“Retinoic acid is available by prescription only and is typically used only to treat acne, while retinol is mostly used in over-the-counter products to promote skin renewal, brighten skin tone, reduce acne, and boost the collagen production.”

Who should use it and who shouldn’t?

“Those troubled by oily skin and acne breakouts as well as those on the lookout of an effective anti-ageing skincare product are suitable candidates,” says Dr Toby Hui, senior aesthetics doctor at Freia Medical.

“However, those with sensitive skin should exercise caution and it’s best to consult with a professional provider for skin analysis and advice before use.”

A power ingredient that has taken the beauty world by storm in recent years, retinol also has a reputation for being a harsh ingredient.

“It’s best to start off cautiously with once or twice a week application. It’s often recommended that you either layer it on top of your moisturiser or mix it together,” Dr Lam shares.

What is the best way to use Vitamin A?

While it’s always best to get a prescription from your dermatologist, those who are keen to try over-the-counter products can pay attention to the retinol concentration when selecting them. Common concentrations found in these products are one per cent, 0.5 per cent, 0.3 per cent, and 0.25 per cent.

“Studies suggest you need to use at least 0.25 per cent retinol or 0.025 per cent tretinoin to be effective. If the percentage of retinol is not listed on the label, it usually means the concentration is weaker than 0.25 per cent,” Dr Lam says.

She recommends starting from the lowest concentration and selecting them specifically to target your skin types and issues.

“One common myth is that retinol and vitamin C can’t be mixed. If both vitamin C and retinol can co-exist naturally in our body, why can’t we use it in the same cream? In fact, Vitamin C stabilises the properties of retinol and together they form a perfect team—the former is responsible for renewing the natural tone and removing any spots that our skin may have and the latter supports regeneration and restoration.”

Are there any side effects to Vitamin A?

Irritation, redness, inflammation and peeling are side effects that can happen with retinoids.

“Though highly efficacious, topical retinoids often exhibit non-tolerable side effects. Some women with darker skin tone complain that their skin is so irritated that it feels and looks ‘burned’ by the retinoids, so it is important to discuss with your aesthetics provider for an appropriate formulation," Dr Hui advises.

A common caution we frequently hear is to avoid sunlight after applying retinol, but Dr Lam shares that it is not impossible.

“The answer is that you can but you must always use sunscreen if you are going to be exposed to the sun—for even as little as 30min—as retinol can produce a sun-sensitising effect. For this reason, if you want to use retinol during the day, always use makeup that includes sun protection.”

What ingredients should it not be used with?

Because retinol is such a potent ingredient, it is important to be mindful of what you pair with it—particularly if you are prone to skin sensitivity.

“Alpha hydroxy acids (AHA) and beta hydroxy acids (BHA) have similar side effects as retinol. When the two powerhouses meet, there can be excessive dryness, redness and skin irritation, so they are best used at different times of the day or different days of the week,” Dr Hui shares.

Benzoyl peroxide, another anti-acne ingredient, can cancel out the effects of retinol when used together, so it is recommended to use it in the day, and retinol at night, he adds.

Read more from The ABCs of Beauty: Vitamin B | Vitamin C | Vitamin D | Vitamin E