Cobalt occurs in small amount in all tissues, higher concentrations occuring in liver and kidneys. Most of the cobalt is present in vitamin B12 which is necessary for red blood cells maturation.
It is largely available in food.
Cobalt deficiency has not been observed in human beings. Cobalt requirements, if any, appear to be met by traces of cobalt found in foods. Human beings require a dietary source of vitamin B12 which is not synthesized by the body.
Cobalt is readily absorbed from the small intestine. About 65% of ingested cobalt is excreted in the urine and the remainder in the feces.
Cobalt deficiency is rare in human beings.