Molybdenum also occurs in traces in human and animal tissues.
Molybdenum is an essential component of the xanthine oxidase. It is also present in nitrate reductase in plants, and nitrogenase, which functions in nitrogen fixation by micro organisms. Trace amount of molybdenum are requried for the maintenance of normal levels of xanthine oxidase in animal tissues.
It is available in average diets.
Adequate amounts of molybdenum are present in average diets. Hence, exact requirement is not known.
About 50 to 70 percent of the ingested molybdenum is readily absorbed in the small intestine. About half of the absorbed molybdenum is excreted in urine.
Molybdenum deficiency is rare in human beings.