Forms of Vitamin A CAROTENOIDS: Precursors forms of vitamin A Found in plant foods: • Is the primary source of Vitamin A from plants foods. • Nutritionally is the most active and most plentiful of the carotenoids. • This is the original substance found in plants (pigments) that animals have eaten and converted to vitamin A • Is called carotene, because one of its main sources is the yellow pigment of carrots