Carotenoids are natural pigments synthesized in plants, algae and photosynthetic bacteria by the polymerization of five-carbon isoprene units to provide a long and nearly symmetric conjugated chain of double bonds responsible for atypical chemical properties. Carotenoids can play an important role in the prevention and control of human health and disease conditions such as osteoporosis, cancer, cardiovascular problems, atherosclerosis, rheumatoid arthritis, muscular dystrophy, cataracts and certain neurological disorders. This book presents and discusses current research in the study of carotenoids.