what is main source 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.itamin A that comes from animal sources is well absorbed and used more efficiently by the body then other sources of the vitamin. The two main sources of vitamin A from animal products are beef liver and turkey giblets. Other sources of this fat soluble vitamin include: 1  Chicken liver. 2  Cod liver oil.