What is Vitamin A?
Introduction to Vitamin A
Vitamin A is a fat-soluble vitamin essential for the normal functioning of the human body. Retinol is one of the most important forms of Vitamin A in cosmetics. It is one of the most important and well-researched anti-aging ingredients in skincare.
Forms of Vitamin A in Cosmetics
Retinoids - Derivatives of Vitamin A
Compounds derived from Vitamin A that function in the skin in various ways:
Retinol (Vitamin A)
- Alcohol form: Retinol is the alcohol form of Vitamin A
- Transformation in the skin: Undergoes a natural process in the skin, transforming into retinoic acids
- Biological effect: Binds to nuclear receptors and initiates cellular changes
Other Retinoids
- Retinoic acid: The most active form, but also the most irritating
- Retinyl esters: A milder option, converts more slowly into the active form
Bio-retinoids
Modern skincare also utilizes bio-retinoids, such as:
- Bakuchiol: Plant-based, non-irritating alternative to retinoids
- Hexapeptide-40 and Polypeptide-76: Synthetic peptides that mimic the effects of retinol
Mechanism of Action of Vitamin A
At the Cellular Level
- Penetration: Vitamin A penetrates the keratinized cells of the skin
- Oxidation: Undergoes a two-phase oxidation process
- Transformation: Converts into the active form of retinoic acid
- Binding: Binds to nuclear receptors (RAR, RXR)
- Biological effect: Initiates the regulation of over 500 genes in the skin
Effects on Cellular Function
- Cell renewal: Enhances cell turnover and the formation of new cells
- Protein synthesis: Stimulates collagen and elastin production
- Differentiation: Guides the maturation process of cells
- DNA repair: Helps the cells' own repair mechanisms
- Gene regulation: Affects hundreds of genes that guide the development of skin structure and function
Sources and availability of Vitamin A
Natural sources
- Animal products (liver, fish, dairy products)
- Vegetables (in the form of carotenoids, which convert to Vitamin A)
Cosmetic use
- Synthetic retinol: Pure form produced in laboratory conditions
- Encapsulated forms: Liposomal or time-controlled release
- Combination preparations: Retinol combined with other active ingredients
Importance for skin health
Different forms of Vitamin A are essential for:
- Maintaining skin structure
- Normal cell renewal
- Collagen production
- Function of the skin's protective barrier
- Regulation of pigmentation
Safety and usage recommendations
Important considerations
- During pregnancy: Vitamin A is not recommended during pregnancy
- During breastfeeding: Caution is advised
- Sun sensitivity: Increases skin sensitivity to sunlight
- Gradual introduction: The skin should gradually get used to the ingredient
Retinization process
Retinization is the process where the skin gradually gets accustomed to the use of products containing active forms of Vitamin A (retinoids). This occurs because the skin initially lacks sufficient functioning Vitamin A receptors. The process may cause:
- Dryness and peeling of the skin
- Possible irritation and redness
- Temporary stinging
- Appearance of pimples
Important: This is not an allergic reaction, but an indication of the skin's unfamiliarity with the active forms of Vitamin A. Most users can eventually use the product regularly without adverse effects.