main sources of vitamin a
There are two main sources of vitamin A, animal sources and plant sources. Known as retinol, animal sources of this essential vitamin contain preformed vitamin A. Vegetable sources contain carotenoids, such as beta-carotene, which is converted to retinol by the body.lant sources of vitamin A include many fruits and vegetables that have rich, deep, intense color. The more intense the color of the vegetable or fruit, the more beta-carotene it contains. Plant sources of carotenes include: 1  Sweet potatoes. 2  Carrots. 3  Pumpkin. 4  Winter squash. 5  Cantaloupe. 6  Pink Grapefruit.