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On this page we look at how Vitamin A is reduced in the skin when exposed to sunlight. The tests were done on human skin, and the results from various studies, as listed below,
have the same conclusion.
On this page
- A solution of 0.5 - 1 µg/ml in hexane irradiated by summer sunlight at noon (32° C) REF 101
Sunlight-induced photodegradation of retinyl esters and retinol in human skin, blood and cultured keratinocytes was investigated. Using high-performance liquid chromatography with an extraction method that avoided saponification, the analysis of human foreskin (Caucasian) showed that levels of retinyl esters and retinol were approximately 3.5 and 5.0 times higher, respectively, in the epidermis than in the dermis. Upon irradiation by sunlight, a significant reduction in epidermal retinyl esters was observed in both summer and winter.
However, epidermal retinol, dermal retinol and dermal retinyl esters did not show statistically significant reductions. When serum from volunteers who had taken a large dose of retinyl palmitate to elevate serum retinyl esters was exposed to sunlight, the retinyl esters in the serum rapidly disappeared after 10 min of exposure--similar to the photodegradation seen for retinyl palmitate in an organic solvent.
While retinol in an organic solvent rapidly photodegraded similar to serum retinyl palmitate, serum retinol slowly declined upon sunlight irradiation. When cultured keratinocytes that took-up 3H-retinol and thereafter contained 3H-retinyl esters and 3H-retinol were exposed to sunlight, 80% of the 3H-retinyl esters disappeared upon sunlight irradiation whereas only about 20% of the 3H-retinol did so.
These results suggest that the epidermis, serum and keratinocytes selectively protect retinol from sunlight-induced photodegradation. It is most likely that serum retinol-binding protein and cellular retinol-binding protein protect retinol, a vital epithelial growth factor, from photodegradation.
- Culture fluid with 3H-Retinol with exposure to summer sunlight at 32° C for 30 minutes. REF 101
- Human skin was exposed in vitro to sunlight for a four hour period. REF 101
- Eleven fair skinned subjects were fully exposed from 1 to 2 p.m. in Johannesburg, South Africa. REF 102
| Subject |
Vitamin A: IU/100 ml blood |
| Before insolation |
After insolation |
2.5 hours after insolation |
| F |
133.9 |
76.5 |
52.2 |
| F |
86.9 |
6.9 |
0 |
| M |
40 |
15.6 |
36.5 |
| F |
40 |
20.8 |
26.1 |
| F |
22.6 |
41.7 |
53.9 |
| M |
45.2 |
41.7 |
38.2 |
| M |
97.3 |
100.9 |
97.3 |
| F |
95.6 |
53.9 |
43.5 |
| F |
13.9 |
19.1 |
13.9 |
| F |
106 |
86.9 |
48.7 |
| F |
22.6 |
6.9 |
0 |
Vitamin A in our skin care products 
We use vitamin A in a selection of our skin care products.
For more information on vitamin A and the products in which it is used, please click here.
To view our complete selection of products, please click here.
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PLEASE NOTE:
Although we quote some animal studies, we at Dermaxime do NOT test any of our products on animals.
For more on animal testing and our stand on this, please click here. |
More Vitamin A information pages
Other ingredient information pages
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