Molybdenum in the Environment and its Relevance for Animal and Human Health

Molybdenum is a ubiquitous element in the environment, and occurs in trace amounts in soil, water, plants, and animals. It is recognized as an essential trace metal for virtually all organisms in view of its functional role as an active cofactor in various bacterial, plant, and animal enzymes. An inborn deficiency of the molybdenum cofactor has been recognized as the origin of a severe syndrome with lethal consequences in the early stages. There is no evidence of naturally occurring nutritional molybdenum deficiency in humans, and efforts in achieving a true molybdenum deficiency in experimental animals were unsuccessful. Molybdenum thiomolybdates can interfere with copper metabolism and induce severe symptoms typical of copper deficiency. This fact is particularly problematic in ruminants, as thiomolybdates are produced in their rumen and can be absorbed in the organism in case of an incorrect balance between dietary molybdenum, copper, and sulfur. The antagonism between thiomolybdates and copper can be exploited for the benefit of human health, for example, for treatment of diseases characterized by copper accumulation in tissues or inhibition of copper-mediated angiogenesis in cancerous tissues.