cobalt (Co) /kō″bôlt/ [Ger, kobold, mine goblin] , a metallic element that occurs in the minerals cobaltite, smaltite, and linnaeite. Its atomic number is 27. Its atomic mass is 58.93. Extensive deposits of cobalt minerals are found in Ontario, Canada. Pure cobalt is obtained by reducing the oxide with aluminum or carbon. It is used in special alloys, such as Alnico. Cobalt is a component of vitamin B12, is found in most common foods, and is readily absorbed by the GI tract. This element is common in the human diet, but the precise daily intake requirement is not known, and cobalt deficiency in humans has not been seen. Cobaltous chloride has been given to some patients with certain types of anemia because of cobalt’s capacity to produce polycythemia. Accidental intoxication by cobaltous chloride, especially by children, may produce cyanosis, coma, and death. Some amounts of cobalt stimulate the production of erythropoietin, by a process not yet understood, but large doses depress erythrocyte production. The only disease for which the use of cobalt is still advocated is normochromic, normocytic anemia associated with renal failure. The radioisotope 60Co or cobalt-60 emits gamma rays and is often used as an encapsulated radiation source in the treatment of cancer.
