Plant scientists at Iowa State University are trying to develop corn fortified with beta carotene to help fight blindness, birth defects and malnutrition in developing nations. The substance is converted by the human body into vitamin A, which is essential for vision, cell division and growth. “Corn is a good way of delivering vitamin A because you deliver it with fats and oils that help in its uptake,” says Stephen Howell, director of the university's Plant Sciences Institute.