<unk> , also known as vitamin<unk> , is a vitamin found in food and sold as a dietary supplement. It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide. These coenzymes are involved in energy metabolism, cellular respiration, and antibody production, as well as normal growth and development. The coenzymes are also required for the metabolism of niacin, vitamin B6, and folate.<unk>  is prescribed to treat corneal thinning, and taken orally, may reduce the incidence of migraine headaches in adults.<unk>  deficiency is rare and is usually accompanied by deficiencies of other vitamins and nutrients. It may be prevented or treated by oral supplements or by injections. As a water-soluble vitamin, any<unk>  consumed in excess of nutritional requirements is not stored; it is either not absorbed or is absorbed and quickly excreted in urine, causing the urine to have a bright yellow tint. Natural sources of<unk>  include meat, fish and fowl, eggs, dairy products, green vegetables, mushrooms, and almonds. Some countries require its addition to grains.<unk>  was discovered in 1920, isolated in 1933, and first synthesized in 1935. In its purified, solid form, it is a water-soluble yellow-orange crystalline powder. In addition to its function as a vitamin, it is used as a food coloring agent. Biosynthesis takes place in bacteria, fungi and plants, but not animals. Industrial synthesis of<unk>  was initially achieved using a chemical process, but current commercial manufacturing relies on fermentation methods using strains of fungi and genetically modified bacteria.
Riboflavin
Folate
Pantothenic acid
Tocopherol
Pyridoxine
Nicotinamide mononucleotide
Biotin
Cholic acid