The use of Vitamin A based products in pregnancy.
By Dr Des Fernandez.
“Basically vitamin A becomes trapped in skin and basically it's not surprising that we have evolved to do this in distinction from all other tissue where vitamin A can be absorbed from the bloodstream and then can get back into it. This is especially true in the liver where we have the enzymes to link vitamin A (as retinol) onto proteins in the serum (basically called retinol biding proteins) and thereby the vitamin A is transported from the liver to other tissues. How exactly the retinol is released is not known but the enzymes required to do that are not the same enzymes as are used to link retinol to serum proteins.
In the skin we do not have the enzyme process to link retinol to serum proteins. Therefore, vitamin A is easily accepted in the skin and it is under physiological conditions easily taken up by cell wall retinoid receptors and transported into the cell where it is basically stored as retinyl esters (usually retinyl palmitate). The retinyl palmitate is metabolised through retinol to retinaldehyde and then close to the nucleus it is further oxidised to retinoic acid. There are nuclear wall receptors for retinoic acid. That’s where virtually all the effects of vitamin A are produced through DNA interaction.
Sorry to start with a somewhat simplified but long-winded outline of the physiology but its important in trying to assess the risks of topically applied vitamin A. The concentration of vitamin A in the creams (even our very strongest ones) are far too low to be of any concern for foetal abnormalities. One has to realise that only a maximum of 6% of topically applied vitamin A will get to the stratum basal and papillary dermis. Then if because the vitamin A is in the ester form generally, it gets accepted by the cellular receptors and enters into the cell. Vitamin A is not taken up into the blood stream. To be absolutely exact, an extremely tiny amount of retinol may be taken up as free retinol into the blood stream. This is extremely, extremely unlikely to be of any concern.
Studies have been done testing radio-labelled retinoic acid and the first time this study was done in the 1980’s they could not detect any retinoic acid in the bloodstream. They repeated the test with much more sensitive instruments in the later 90’s and they had a minute number of labelled molecules that they detected. These studies are what has helped me to understand the safety of vitamin A. However, like Johnson and Johnson and other retinoic acid companies, we recommend that Environ should not be used in the first trimester, not because we feel there is any risk, but rather because we do not want to be exposed to legal claims from mothers who have had babies with some malformation totally unrelated to vitamin A. The conditions described are limb abnormalities and cleft palate. All of my friends and very many young women using retinoic acid for acne have had normal pregnancies while continuing to use vitamin A. I believe it also helps to reduce the chance of developing stretch marks, but I admit that if the mother does not get stretch marks how can we be certain that she would have developed them if she did not use vitamin A!
So in summary, I believe personally that there is not risk in using vitamin A creams (Environ) during pregnancy. I have consulted with foetal research units about this and they simply laughed at my question. However,I always tell mothers that they can simply stop vitamin A for the first trimester.
Next, during lactation, many people use vitamin A creams (usually the low dose products) on their nipples to treat cracked nipples while breast-feeding. I believe that the baby just gets a minute dose of vitamin A which is not bad seeing that vitamin A deficiency is such a fatal risk and is also so common around the world. A study in Japan showed that in this first-world country that eats a lot of vitamin A-rich fish, the general population was probably at about 80% of ideal levels of vitamin A and this is made worse for women in pregnancy because the basic advice in Japan is to tell pregnant women to avoid vitamin A. Most likely women are rather under-nourished in vitamin A but of course the placenta ensures that the baby gets as much vitamin A as possible to the detriment of the mother.
Topical vitamin A is safe because it has a very low penetration and then is not transported into the blood stream.
If a mother is really concerned and still want to use topical products with active ingredients I recommend an antioxidant mixture with carotenoids (beta-carotene is “plant vitamin A”).”