Canthaxanthin is a keto-carotenoid pigment and potent lipid-soluble antioxidant widely distributed in nature. Canthaxanthin has been found in edible mushrooms green algae, bacteria, crustaceans, and bioaccumulates in fish such as carp, golden mullet, seabream and trash wrasse. Canthaxanthin is used to reduce sensitivity to sunlight (photosensitivity) experienced by people who have a rare genetic disease called erythropoietic protoporphyria (EPP). In these people, sunlight can cause skin reactions such as rash, itch, and eczema. Canthaxanthin is also used to reduce sun sensitivity caused by certain medications. Some people also try it for relieving itching caused by sun exposure. Canthaxanthin is associated with E number E161g and is approved for use as a food coloring agent in different countries, including the United States and the EU; however, it is not approved for use in Australia and New Zealand. It is generally authorized for feed applications in at least the following countries: US, Canada, EU. In the EU, canthaxanthin is allowed by law to be added to trout feed, salmon feed, and poultry feed. The European Union limit is 80 mg/kg of feedstuffs, 8 mg/kg feed for egg-laying hens and 25 mg/kg in feed for other poultry and salmonids.