Vanadium (V) is a steel-grey, corrosion-resistant metal. Because of its hardness and its ability to form alloys, vanadium (i.e., ferrovanadium) is a common component of hard steel alloys used in machines and tools. Although most foods contain low concentrations of vanadium (< 1 ng/g), food is the major source of exposure to vanadium for the general population. Vanadium is probably an essential trace element, but a vanadium-deficiency disease has not been identified in humans. At pharmacological doses, vanadium compounds display relevant biological actions such as mimicking insulin and growth factors as well as having osteogenic activity. Some vanadium compounds also show antitumoral properties.