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Wednesday
Aug312011

The Vitamin A Controversy

Recently, the EWG Skin Deep Cosmetics Database increased their hazard score for two forms of Vitamin A, Retinol and Retinyl Palmitate to an eight (high hazard) for both ingredients.  Is there science behind this decision? Should we be concerned about Vitamin A?  Let's get to the bottom of the Vitamin A controversy. 

According to EWG, "a 2009 study by U.S. government scientists suggests that a form of vitamin A, retinyl palmitate, when applied to the skin in the presence of sunlight, may speed the development of skin tumors and lesions (NTP 2009, 2011)."  While they do say that these are preliminary animal studies and human studies have not been done, EWG is pushing the industry to discontinue the use of Retinyl Palmitate in sunscreens, and pushing the FDA to ban or regulate its use.  The FDA claims that more studies need to be done to conclusively verify any risks. 

In 2005, the molecular mechanism whereby retinyl palmitate possibly creates free radicals was discovered.  It was found that in visible and UV light, retinyl palmitate broke down to create two free radical species, anhydroretinol and 5,6-eposyretinyl palmitate that were able to mutate DNA. Other studies have verified that these decomposition products are photomutagenic.

So, now what about retinol, the more natural form of vitamin A?  While this 2010 study did find that retinol was photomutagenic, it was in mouse lymphoma cells, which obviously have a different metabolism that of human skin.  This study found that "sunlight-induced photodegradation of retinyl esters proceeds much faster than that of retinol, and it has been suggested that cellular retinol binding protein (CRBP) protects retinol from photodegradation."  In other words, a protein in the skin is able to bind retinol so that it doesn't break down and create free radicals like retinyl palmitate does.  So, I would deem retinol to be a safer form of Vitamin A than the synthetic retinyl palmitate. (In my opinion it should score maybe a 4 instead of an 8.) However, Vitamin A creams should be used with caution, as the studies are still conflicing and the subject is still being studied. 

[Other forms of vitamin A, such as beta-carotene (as found in rosehip seed oil) were not found to create photodegredation-induced free radicals.] 

 

Reader Comments (4)

Is this Retinyl Palmitate the same as (or related to) the "Vitamin A Palmitate" found in some low-fat dairy products? If so, would the risks be the same for ingesting it rather than it being absorbed into skin? I have seen it on labels for milk, sour cream, etc. and have been curious.

Thu, September 1, 2011 | Unregistered CommenterKelly P.

In the above article I mentioned how some forms of Vitamin A, the metabolic precursors to retinoic acid, do not have the photosensitivity issues that other forms of Vitamin A have, especially if they are formulated correctly to penetrate into the dermis where they can be stored until the body needs to convert them to retinoic acid. They also do cause long-term dermal thinning, less risk of toxicity, and are more tolerable to those using them.

Thu, September 1, 2011 | Unregistered CommenterRachael Pontillo

I would appreciate more specific advice in this article and others like it, than "use with caution".
What does that mean?
- Keep its use limited? How much and why?
- Use along with another cream?
- ?

Sat, September 3, 2011 | Unregistered CommenterSusan M.

Now I lost faith and trust on skin deep website. I don't believe vitamin A for women who are not trying to get pregnant and in normal levels are TOXIC.

IN HIGH LEVELS IT CAN BE TOXIC TO THE LIVER AND EVEN CAUSE ACNE.

THESE FAKE STUDIES WENT TOO FAR.

Sun, September 2, 2012 | Unregistered CommenterMarcia B.

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