Carotenoids are chemicals that have nutritive properties and that exist in the pigment that colors plants and animals. As fat-soluble materials, carotenoids are ingested by humans in countless colorful fruits and vegetables. They are important as antioxidants and for their capacity to get converted to essential vitamins. Many health experts say that people should receive carotenoids by eating fresh fruits and vegetables as part of a healthy diet, rather than by taking supplements, because they are easier for the human body to use when ingested in natural foods.