Vitamin A can serve as a keratinization regulator, improving skin texture, firmness, and smoothness. When in the skin, vitamin A esters convert to retinoic acid, which has anti-ageing properties. Vitamin A is thought to be essential for the growth and function of skin cells. Continued vitamin A deficiency causes dermal tissue degeneration, and the skin becomes thick and dry. Surface application of vitamin A helps avoid skin dryness and scaliness, keeping the skin smooth, clear, and infection-resistant. When combined with vitamin E, it appears to have improved skin regeneration properties.