Uncovering the essentials for healthy skin
by Gül Ç. Zone
In 1911 Casimir Funk, a Polish biochemist, coined the word “vitamin” while doing research on preventing nerve inflammation at the Lister Institute in London. He identified a member of the amine chemical family as being capable of reducing neuritis in patients. He termed the compound a “vitamine,” given its vital role in life. The “e” was later dropped as it was recognized that not all vitamins are amines. Today’s definition of vitamins can be summarized as organic compounds that are essential to humans and some plants for normal growth and nutrition.
“Vitamins are vital for the well-being of the eyes, heart, nervous system and connective tissue, which includes the skin.”
With the exception of vitamin K, each new vitamin was assigned a letter in alphabetical order of its discovery. Most of these vitamins were discovered in the study of diseases, where the absence of specific chemicals was found to be the culprit. Some vitamins can be synthesized in small quantities by the body, but most must be derived from the diet.
Vitamins typically function as co-enzymes in biochemical processes, in addition to acting as signaling molecules, powerful antioxidants and hormones. Furthermore, they can serve as carriers for electron transport and carbon dioxide transfer, which controls cellular energy and metabolism. Vitamins are vital for the well-being of the eyes, heart, nervous system and connective tissue, which includes the skin.
Vitamins can be classified by their solubility with water (hydrophilic – water loving) or oil (lipophilic – oil or fat loving). Lipophilic or fat-soluble vitamins include vitamins A, D, E and K. Their chemical structure is substantially built on carbon and hydrogen chemistry typical of fat compounds. Ingested lipophilic vitamins have an affinity for fatty tissue. Adipose (fat) tissue is the second largest storage site for vitamin A after the liver. As a result, over-consumption of fat-soluble vitamins can cause toxicity, as they are stored in the fat and take longer to clear the body. Watersoluble vitamins must be delivered to the body every day in small, controlled doses, as excess amounts are excreted.
Water soluble vitamins differ from the fat-soluble molecules by having polar functional groups including nitrogen and oxygen, which typically have a high affinity and impart solubility in water. In terms of skin care formulations, the water versus fat-solubility of a vitamin determines their rate of permeability within skin and the delivery method (e.g., microgel or lotions).
Vitamins A, B, C, D, E, K and P are all essential to healthy skin, either via nutritional intake or topical application. Let’s examine each vitamin, its chemical structure, delivery system and specific skin benefits.
The great normalizer, vitamin A is essential for all skin types and many skin conditions. The common form of vitamin A in the body is retinol (vitamin A1), which is derived from vitamin precursors such as carotenoids (e.g., Carotene) and retinyl esters (e.g., retinyl palmitate), which must be derived from the diet. Once formed, retinol is converted to retinoic acid, which when taken up by an epidermal basal cell stimulates its replication and differentiation. An absence of vitamin A in the diet has a deleterious effect on skin health, vision and other physiological functions.
At normal levels, vitamin A stimulates epidermal turnover and exfoliation, which leaves the skin smooth and reduces wrinkles, pigmentation, psoriasis, eczema and dehydration, while optimizing protection of the skin given its antioxidant properties. By stimulating exfoliation, it helps lift and remove pigmented melanin granules to reduce brown spots and other forms of hyperpigmentation. It has been shown to decrease sebum production in the treatment of acne, and to boost blood flow to improve redness and rosacea. This multi-purpose vitamin plays a key role in cellular turnover, differentiation and growth regulation.
The B-complex vitamins make up a group of eight vitamins: thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), cyanocobalamin (B12), folic acid and biotin. B3 and B5 are the most critical for the skin via topical delivery. A deficiency in any one of these vitamins can manifest itself in dry skin, mouth and lips, chapped skin and sometimes sores. Since vitamin B is hydrophilic and is not stored in the body, it must be replenished via dietary intake.
Vitamin B3, niacin or nicotinic acid, can also exist as an amide known as nicotinamide. Both forms are hydrolyzed by the body. Niacin is used to make hormones and stimulate cellular metabolism. It has been shown to improve circulation and suppress inflammation in the skin, and is helpful for acne, rosacea and aging.
Vitamin B5, pantothenic acid, is needed by the body to produce Coenzyme A (CoA), which is required by at least 70 enzymes to function properly. In the skin, pantothenic acid is derived from panthenol through an enzymatic process and utilizes it as needed. A great hydrator, vitamin B5 is highly effective for moisturizing and wound healing. It is recommended for all skin types including dry and sensitive, rosacea and skin prone to breakouts or hyperpigmentation due to inflammatory processes.
Vitamin C, also known by its chemical name “ascorbic acid,” is a catalyst for many biochemical reactions in the body. It is vital to the production of collagen found in the bones, fibrous and connective tissue, capillaries and the skin. Nutritional deficiency of vitamin C can lead to scurvy, which can disrupt wound healing and cause joint pain and muscle loss.
In the skin, collagen is manufactured in the dermis by the fibroblast cell. Vitamin C is a co-factor in the final biosynthesis of collagen fibers in the dermis, and also helps stimulate the synthesis of the enzymes needed to produce new collagen. Just as importantly, vitamin C has been shown to inhibit the enzymes responsible for breaking down collagen. As skin ages, the production of new collagen slows, becomes more disorganized and is susceptible to degradation by collagenase enzymes that are responsible for breaking down collagen. Exposure to UV radiation further accentuates these intrinsic aging processes. With the reduction in new collagen and collagen organization, skin loses a key component of its scaffolding and bulk.
Vitamin C or its analogs (ascorbyl palmitate and acetate) are vital in a daily skin care regimen to control all signs of aging including wrinkles, lost elasticity, hydration, firmness and hyperpigmentation and to provide photo protection. In addition to its role in collagen biosynthesis, vitamin C reduces skin pigment irregularities by inhibiting the function of the key enzyme tyrosinase involved in the synthesis of the pigment melanin in the epidermis. This key vitamin provides beneficial effects to the skin via both the stability and permeability of the molecule.
Known as the “sunshine” vitamin, vitamin D is produced by the absorption of sunlight (specifically UVB) through the skin, converting a form of cholesterol to vitamin D in the epidermis. It is subsequently converted to 1, 25-dihydroxyvitamin D3, the more potent form of the vitamin. Inside the epidermis the 1, 25 vitamin D3 associates with epidermal receptor sites similar to those used by vitamin A, allowing it to regulate the production and proliferation of new epidermal cells. Its ability to inhibit the proliferation of skin cells may play a role in preventing the proliferation of cancerous skin cells.
Vitamin D has numerous other functions in the body, including regulating the absorption of calcium and phosphorus, making it critical to bone, muscle, thyroid and skin health. There are vitamin D receptors in skin as well as on cells in the immune systems. When vitamin D binds to the skin receptors, it increases the amount of good microbes, which help fight off the bad microbes — thereby providing antibacterial protection to the skin.
When vitamin D binds to the receptors of the immune system, it reduces the levels of cytokines, proteins that typically become elevated during an inflammation process. Studies have found that vitamin D reduces the inflammation and irritation associated with psoriasis, and that low levels of vitamin D are associated with eczema.
Aging decreases the skin’s ability to produce vitamin D, so it is imperative to supplement vitamin D intake.
Vitamin E is a powerful lipophilic antioxidant, which prevents oxidative damage to cellular membranes and other cellular bodies. Vitamin E is an excellent topical protectant against photo damage as it can absorb ultraviolet (UV) light. This makes it a powerful vitamin to fight skin aging and hyperpigmentation. As an antioxidant vitamin E neutralizes reactive oxygen species or “free radicals” by donating its own electron to stabilize and “neutralize” free radical species. In turn, it has the capacity to replenish its donated electron from other vitamins. It has a unique synergy with other antioxidants, such as the ascorbates (vitamin C), retinols (vitamin A) and coenzyme Q10 (Ubiquinol). All skin types can benefit from a combination of vitamin C and E topicals. These should be in high concentrations of bio-available forms for maximum effectiveness.
Vitamin E has been shown to mitigate inflammation by decreasing prostaglandin synthesis, interleukin production and induction of cyclooxygenase- 2 oxidase. It has also been shown to reduce skin swelling, erythema and edema caused by UV induced inflammation.
Vitamin K is the only vitamin that was named after its function — “Koagulation” — the German word for “coagulation,” rather than the alphabetical order in which it was discovered. Essential to the formation of blood clotting factors, vitamin K is also involved in bone, vessel and cellular health. Unlike other fat soluble vitamins, vitamin K is stored in the body in very small quantities and must be supplemented nutritionally.
Vitamin K’s contribution to skin care is a reduction of spider veins, enlarged capillaries just below the surface of the skin, and discoloration under the eyes. Spider veins are believed to be the result of the micro-vessels under the skin weakening, whereas discoloration is thought to result in micro-seepage of blood from surface capillaries. Vitamin K is believed to strengthen the vessels, preventing both spider veins and reducing the vessel permeability and leakage.
Vitamin P is a bioflavonoid, originally discovered during the first isolation of vitamin C. Given the letter “P” due to their ability to reduce capillary permeability by strengthening them, vitamin P is a large family of polyphenolic plant compounds. Flavonoids are subdivided into flavones, flavonols, isoflavones and flavones, each with a slightly different chemical structure. The major subclasses of flavonoids include anthocyanidins, flavan-3-ols, flavanols, flavannes and isoflavones. These are derived from plant sources like fruits and vegetables. Due to their activity on capillaries, they have proven effective at reducing spider veins, which are due in part to the degradation of these micro-vessels.
Good health requires a diet and topical routine rich in vitamins. Vitamins have powerful effects on a wide range of tissues, including skin and other connective tissues core to the nervous, vascular and skeletal systems. Maintaining a base level of vitamins prevents diseases, and also slows natural or intrinsic aging processes, particularly given their antioxidant and anti-inflammatory properties. Vitamins are critical in repairing the effects of intrinsic and extrinsic aging on skin. Due to their chemical structure and permeability, continuous delivery is important to maintain UV and free radical protection.
The preventive and corrective value of vitamins makes them essential to a complete topical skin care regimen for all ages and skin types. The key to these beneficial results requires daily use at the correct dose in a stable delivery system that can incrementally be increased with age. So encourage your clients to eat for health and never neglect their daily topical vitamins!