The most abundant of the carotenoids, beta-carotene has strong provitamin A activity and is a stronger antioxidant than vitamin A. It is widely accepted today as a cancer preventative. It is found in leafy green and yellow vegetables, often missing in children’s diets. Beta-Carotene is believed to be a superior source of Vitamin A because it is readily converted into a more active form of the substance: your body converts it to Vitamin A as needed.