Vitamin A is a fat-soluble vitamin that is an essential nutrient. The term "vitamin A" encompasses a group of chemically related organic compounds that includes retinol, retinyl esters, and several provitamin carotenoids, most notably Beta -carotene.Vitamin A exists in two main forms in food: preformed vitamin A, found in animal products, and provitamin A carotenoids, found in plants. Preformed vitamin A is readily absorbed and used by the body, while provitamin A carotenoids need to be converted to vitamin A within the body.Many foods are good sources of vitamin A, including liver, sweet potatoes, carrots, spinach, . Animal products like