The ABC’s of Skin Care: How Our Bodies Use Vitamin A
If your vitamin A levels are up to snuff from the foods you eat, adding more probably will not do much more for your skin. That said, if those levels drop even a little below average, you are likely to see some skin-related symptoms, including a dry, flaky complexion.
Vitamin A is an umbrella term for an important class of antioxidants and is used to generically describe compounds that exhibit the biological activity of retinol, the alcoholic form of vitamin A. Vitamin A was first discovered in 1913 and today it is known to be important for several health issues. Not only does Vitamin A contribute to proper cell growth and repair, particularly of skin cells, but is also essential for strengthening night vision, assisting bone growth, and regulating the immune system.
Let’s take a look at the scientific aspects of Vitamin A when taken internally.
In the body: Vitamin A and its derivatives support cell growth and repair by reducing the oxidation of DNA, protecting cells from free radical damage, assisting with immune function, and maintaining and repairing epithelial tissue through cell differentiation (a normal process through which cells mature) and its role in gene expression. By affecting gene expression, vitamin A can determine what type of cell an immature cell will become.
DNA (deoxyribonucleic acid): an extremely long macromolecule that is the main component of chromosomes and is the material that transfers genetic characteristics in all life forms, constructed of two nucleotide strands coiled around each other in a ladder-like arrangement.
Cellular Differentiation is the process where a cell changes from one cell type to another.
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product.
A gene product is a biochemical material, either RNA or protein, resulting from expression of a gene. A measurement of the amount of gene product is sometimes used to infer how active a gene is.
Also, protein cannot be utilized by the body without the presence of vitamin A. ~ When protein is deficient, the amount of retinol-binding protein (which binds to vitamin A and transports it from the liver to other tissues in the body) made is inadequate. And, without vitamin A, epithelial cells which make up the skin cannot differentiate normally because there is no vitamin A to regulate the production of particular proteins. Functions of epithelial cells include secretion, selective absorption, protection, transcellular transport, and sensing.
In the skin: A deficiency of vitamin A can lead to dry skin, but also to broken fingernails, dry hair and eyes. Because vitamin A increases cell proliferation and turnover, skin problems which result in a buildup of scaly or horny skin (keratinizing), such as eczema and psoriasis, may benefit from vitamin A supplementation either topically or orally.
Retinoids, chemical compounds that are related to vitamin A, are often applied topically to the skin to treat acne, minimize the appearance of wrinkles, bolster skin’s thickness and elasticity, slow the breakdown of collagen (which helps keep skin firm), and lighten brown spots caused by sun exposure.
In more technical terms, retinoids work by binding to specific retinoic acid receptors (RARs) or RXRs [retinoic X receptors] in your skin and activating them. ~ The activation of these receptors results in collagen production and/or skin desquamation, etc.
Different receptors do different things when they are activated. Therefore, retinoids improve the way your skin sheds and renews itself by binding to and activating these RARs. Think of them as cell-communicators that tell your skin cells to behave in the best way possible.
So there you have it!
Vitamin A is necessary for the maintenance and repair of skin tissue… and plays a huge role in the overall health of our skin, nails, hair, and eyes.
~ This excerpt is adapted from the article: The Science of Skin: Skin Care from the Inside Out, which was written by Tasha D. Manigo-Bizzell, a licensed aesthetician, makeup artist and originally published in DERMASCOPE Magazine and on DERMASCOPE.com and is copyrighted by WES Publishing Co.