Carotenoids are a widely distributed group of naturally occurring pigments, usually red, orange or yellow in color. They are used extensively as safe, natural colorants for food, feed, and cosmetics. They are known to be essential for plant growth and photosynthesis, and are a main dietary source of vitamin A in humans. They are thought to be associated with reduced risk of several chronic health disorders including some forms of cancer, heart disease and eye degeneration. Listed alphabetically are the names of some of the most common naturally-occurring carotenoids. Click on the name to view the structure of the molecule.