TOPICAL VITAMINS FOR SKIN
Vitamins are organic compounds required in tiny quantities for normal function also obtained from the diet. Vitamins for skin are mostly active agents in skin care products designed to improve skin appearance. So vitamins have been used in cosmetic products and certainly, there is the rationale for such use since they have beneficial effects across a wide spectrum of skin problems. There needs to be careful formulation when using vitamins to prevent loss of activity through photoinactivation or premature oxidation.
Many types of vitamins for skin care are used cosmetically. The most popular ones are retinyl esters, retinol, and retinaldehyde. Vitamin A fight cancer, reduce wrinkles, increase blood flow, and is anti-aging. Through endogenous enzymatic reactions, all are turned to trans-retinoic acid, the active form of vitamin A in the skin. To stimulation of events in the skin, retinoids have an inhibitory effect on other tissue components. Retinoids are can also inhibit production of collagenase. Retinoid can stimulate the production of a ground substance in the epidermis, but it will have excess ground substance in the photoaged dermis. Retinol is tolerated by the skin than trans-retinoic acid. Because retinoids tend to be fairly potent, topical doses of less than 1% can have significant effects.
There are three primary types of vitamin B that have found utility in vitamins for skin care products; nicotinate esters, niacinamide, and nicotinic acid. Vitamin B serves as a precursor to a family of endogenous enzyme cofactors. Vitamin B role may be the basis for the diversity of clinical effects observed for a material such as niacinamide. Niacinamide inhibits sebum production specifically affecting the content of triglycerides and fatty acids. This could be a contributor to the observed reduction in the skin texture and pore size. Niacinamide can speed up the epidermal production of skin barrier layer proteins and their precursors going to the observed enhancement of barrier function as determined by reduced transepidermal water loss. This new barrier also increases skin resistance to environmental insult from damaging agents like leading to less irritation, skin redness, and inflammation. Since inflammation is a skin aging problem, the barrier might contribute to anti-aging effects of topical niacinamide. Niacinamide increases production of collagen which may contribute to the reproduction in the appearance of wrinkles in the skin.
Vitamin C is one of the known vitamins for skin and acts as an antioxidant and has been utilized as a skin lightener. It also is known for having anti-inflammatory properties because it reduces the erythema associated with postoperative laser resurfacing. There are many studies that talk about anti-aging effects of ascorbic acid such as reduced UVA-induced oxidation and reduction in skin aging appearance parameters. The challenge with vitamin C compounds, in general, is stability, mostly with ascorbic acid. In spite of all those approaches in general ascorbate, stability remains a challenge, and some of these approaches can lead to unwanted esthetic skin effects such as irritation.
Vitamin E is one of the important vitamins for skin known as tocopherol and is an antioxidant. There are many isomers based like one number and position of substituents on the phenyl ring. The active form is free tocopherol, so topical use of esters such as tocopherol acetate would require enzymatic hydrolysis to free vitamin o or in the skin for maximal activity. Since its lipid soluble its site of action is more likely to be in lipid-rich environments. Even though vitamin E is often used as a preservative stabilizer in the formulation at relatively high topical doses it’s quite effective in preventing oxidative damage to skin just like preventing acute and damage from chronic UV radiation.
OTHER VITAMINS FOR SKIN
There's a lot of vitamin D compounds and many synthetic variations. Dehydrocholesterol is a cosmetically used material which can be converted into active vitamin D upon exposure to UV light. A result of the effects of vitamin D compounds on epidermal growth and differentiation there has been a discussion of their skin barrier and photodamage mitigation activities as seen in vivo model testing.
There are many types of vitamin K such as phylloquinone and menaquinone. Vitamin K compounds function in blood clotting, and there are data showing effects for mitigating bruising along with speculation about the use of them in improving other problems in the skin like the dark circles under the eyes. However, there are no studies that support that latter use. Oxidative stability is a concern with maybe some vitamin K compounds.