Vitamin A, a fat-soluble micronutrient, exists in various forms, including retinol, retinal, and retinoic acid. It is essential for numerous physiological functions, including vision, immune system support, and cellular differentiation. Vitamin A is found in both animal-derived sources, such as liver and dairy products, and plant-based sources, in the form of provitamin A carotenoids like beta-carotene.