Vitamin A on the Skin: What Is Retinol?

1. What Is It Actually?

Vitamin A is a tiny building block. It is so small that you cannot see it – smaller than a crumb from a biscuit. “Retinol” is another name for this vitamin; both words mean the same thing.

“Topical” is a technical term and means: on the skin. A topical cream with vitamin A is therefore applied to the skin. It stays there and is not eaten. That is exactly what makes it different from a vitamin that enters the body through food.

Vitamins are substances that living beings need in small amounts – like small tools in a large workshop. A cream usually contains only a tiny proportion of vitamin A. The rest is fat, water and other ingredients so that the cream spreads well and the vitamin does not disappear too quickly.

Researchers assume that only part of the vitamin reaches the uppermost layers of the skin. What exactly happens there is still an open question. That is precisely why researchers look so closely.

2. Where Does It Come From?

Vitamin A is a natural substance. That means: it occurs in nature, and humans can also produce it themselves. For a cream it is manufactured and mixed with other ingredients.

This produces an ointment, a cream or a gel. Ointment is greasy and thick, cream is softer, gel is transparent and cools the skin a little. In the end the mixture goes into a tube or a small jar with a lid.

Because all tubes are mixed in the same way, each contains roughly the same amount of vitamin A. This is important for researchers: only then can they compare what the cream does on the skin. If every jar contained something different, no one would know in the end where a difference came from.

3. What Do the Researchers Investigate?

Researchers want to know what happens on the skin when vitamin A meets it. They look, for example, at whether the skin changes, whether it feels different or whether it becomes red. The comparison is important here: one group receives the cream with vitamin A, another receives a cream that looks the same but contains no vitamin A. This second group is called the comparison group.

More than a hundred studies have been carried out with people; in thirty-seven of them there was such a comparison group. Each one of them required work, time and care. Small studies are hints: they show a direction, nothing more. A hint can later lead to a large study.

Some things are already known quite well, others not at all. A hypothesis – that is, an idea that is still being tested – is: vitamin A on the skin could influence the uppermost skin layers. Whether this is true and for whom it applies is still open. This is not a weakness of the research, but the next question.

4. An Experiment to Think About

Imagine you want to find out whether a cream has an effect on the skin. What would you do? One idea would be: you need many people, not just one person. One half receives the cream with vitamin A, the other receives a cream that looks and smells the same but contains no vitamin A. And no one is allowed to know who has which cream – not even the researchers. Only when the jars are opened does it become clear whether there was a difference.

Ask yourself: what would you measure? The colour of the skin? A photograph taken the same way every day? Or how the skin feels when someone strokes it? Researchers think about such questions for a long time. This is a thought experiment – you do not have to try it out.

For adults and professionals: the detailed page on Topical Vitamin A (Retinol).