Beta carotene is called provitamin a, which can be converted to retinol by the body n the liver, one molecule of beta carotene can be cleaved by an intestinal enzyme into two molecules of retinol so beta carotene can also be good sources of retinol• Beta carotene is called provitamin A, which can be converted to retinol by the body. • In the liver, one molecule of beta carotene can be cleaved by an intestinal enzyme into two molecules of retinol, so beta carotene can also be good sources of retinol