Beta Carotene is a precursor to vitamin A, that is, your body converts carotene into vitamin A. Many multivitamin mixes include Beta Carotene as well as vitamin A but not all people can utilize this nutrient. Diabetics, those with a low thyroid, those with severe liver problems, and blood Type A cannot convert beta carotene to vitamin A. Beta carotene nourishes the soft tissues such as gums, eyes, and lungs. It is a powerful antioxidant. Food sources are carrots (where it was first isolated-thus the name carotene), yellow, red and dark green fruits and vegetables.