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On this page we look at how topically applied Vitamin A acts as a bioregulator of keratin formation in the skin. The tests were done on human epidermal cells, and
show conclusively that topical vitamin A helps to regulate keratin formation in the skin.
- In vitro test with human epidermis cells where Vitamin A acetate was applied to the culture fluid. REF 100
Vitamin A is known to exert an important influence on epithelial differentiation. The fetal calf serum supplement of cell-culture medium contains enough of the vitamin to affect the differentiation of cultured keratinocytes derived from epidermis and from other stratified squamous epithelia.
The cellular and molecular properties of the cultures are altered when the medium is supplemented with serum from which the vitamin A has been removed by solvent extraction (delipidized serum).
Cell motility is reduced, the adhesiveness of cells increases and pattern formation is prevented. In both epidermal and conjunctival keratinocytes, removal of vitamin A leads to the synthesis of a 67 kd keratin characteristic of terminally differentiating epidermis and to much reduced synthesis of the 52 kd and 40 kd keratins typical of conjunctiva.
These changes, both cellular and molecular, are reversed by the addition of retinyl acetate to the medium containing delipidized serum. Cell motility and pattern formation are restored, and detachment of the most mature cells from the surface of the stratified epithelium is promoted.
Synthesis of the 67 kd keratin is prevented and the synthesis of the 40 and 52 kd keratins is stimulated. The nature of the keratins synthesized is regulated by the concentration of vitamin A, and each cell type adjusts its synthesis differently at a given vitamin concentration.
| Keratin |
Keratin Spectrum of Epithelium in % |
| Molecular weight kd |
Normal epithelium |
Epithelium grown with too high Vitamin A concentration |
Epithelium grown with some Vitamin A |
Epithelium grown without Vitamin A |
| 40 |
5 |
1 |
10 |
.05 |
| 46 |
5 |
21 |
18 |
21 |
| 50 |
10 |
15 |
20 |
15 |
| 52 |
12 |
5 |
10 |
1 |
| 56 |
15 |
28 |
20 |
29 |
| 58 |
22 |
30 |
22 |
25 |
| 67 |
31 |
0 |
0 |
8.5 |
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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