Normal average diet contains about 5-8 micro gm of cobalt, which is more than the recommended daily allowance (1-2 micro gm of vitamin B12 contains approximately 0.045 to 0.09 micro gm of cobalt). It is found in animals and not present in vegetables. Its absorption is 70-80% of dietary cobalt; cobalt is stored mainly in the liver, being the principal storage site. Only trace amount present in other tissues. Food containing cobalt includes meat, milk, eggs, cabbage and sheep.
Vitamin B12 is essential for producing red blood cells and maintaining the nervous system, cobalt activates metabolic enzymes and myelin sheath formation (an insulating layer around nerves) & thyroid hormone production. It is essential for the metabolism of fats & carbohydrates, synthesis of protein, production of DNA & RNA, conversion of folate to its active form. It is also used by athletics to increase the oxygen carrying ability of the blood. In formation of co-enzyme, cobalt of B12 undergoes successive reduction in series of step catalyzed by the enzyme “B12 reductase” which requires NADH & FAD. It is used in anemia, myelin formation, nerve regeneration, RBCs production & reducing tumor growth. It increases the body weight & appetite. Thus cobalt is a very important trace element used for various biological activities. In addition, cobalt may be transferred from the pregnant mother to the fetus or from the mother to the infant in the breast milk. Studies in animals have suggested that children may absorb more cobalt from foods and liquids in comparison with adults.