You cannot normalise skin without vitamin A, it’s built into our genes. We absolutely need it to make skin cells function normally as the ultra-important Vitamin A-responsive genes respond to nothing else. We are all born with rich levels of retinoid receptors on our cells, but sun exposure depletes them. That is why children under the age of about 4 years, do not get retinoid or vitamin reactions. Vitamin A, paradoxically, is the only way to build up more receptors. Vitamin A causes a reaction (the retinoid reaction) only when the natural Vitamin A receptors on cells are degraded, generally by sun exposure.
Some people are born with irregularities in their vitamin metabolism but eventually, as enough Vitamin A receptors become active, the skin becomes healthier and healthier and gets to the normal levels of Vitamin A found in young children
Retinol is the chemical name for Vitamin A. It is the alcohol form of Vitamin A which gets changed mainly to retinyl esters inside cells. A tiny percentage of topically applied retinol gets converted into the active version, retinoic acid – the acid version of vitamin A that works on the DNA.
Retinol largely exerts the effects of Vitamin A on the skin, depending on its concentration. Virtually every bit of retinol applied to skin is converted to retinyl palmitate in the cell and is then slowly metabolised in the cell to retinol again, then retinaldehyde and finally into retinoic acid – that is where Vitamin A exerts its effects on the DNA.
The only sure way to avoid the retinoid reaction in older people is to start at the lowest dose and gradually work up, as the skin restores Vitamin A receptors. With a sensitivity or allergy, the longer you use the Vitamin A the worse it gets. With a retinoid reaction, the longer you continue to use Vitamin A, the less the reaction. A retinoid reaction is a simple chemical irritant reaction because the Vitamin A remains outside the cell, which causes the irritation. If the vitamin A is absorbed into the cell, then there is no reaction. The paradox of Vitamin A is that the people who are most depleted and in most need of restoring their vitamin levels, are also the people who will get a retinoid reaction. Introducing Vitamin A gradually specifically addresses this problem.