Molybdenum

Molybdenum is a chemical element; it has symbol Mo and atomic number 42. Molybdenum is an essential trace element that is naturally present in many foods and is also available as a dietary supplement. Molybdenum is a structural constituent of molybdopterin, a cofactor synthesized by the body and required for the function of four enzymes: sulfite oxidase, xanthine oxidase, aldehyde oxidase, and mitochondrial amidoxime reducing component (mARC).

The kidneys are the main regulators of molybdenum levels in the body and are responsible for its excretion. Molybdenum, in the form of molybdopterin, is stored in the liver, kidney, adrenal glands, and bone.

Molybdenum-related cattle sickness, often linked to a condition called molybdenosis or secondary copper deficiency, is a phenomenon and has been documented in the United States and other parts of the world. Its concentration in soil varies depending on geology, with higher levels in areas with certain rock types or industrial contamination. Plants can absorb molybdenum from the soil, and levels in forage can become elevated in regions with naturally high molybdenum or human-induced contamination.

Cattle require trace amounts of molybdenum for metabolic processes, but excessive intake can be harmful. High molybdenum in forage disrupts copper metabolism in ruminants like cattle, leading to a condition known as molybdenosis. This is often a secondary copper deficiency because molybdenum forms complexes with sulfur in the rumen, creating thiomolybdates that bind copper, making it unavailable to the animal.