ABSTRACT
Vanadium is abundant in the biosphere, where it has a well-defined function in some biological systems. It also has pharmacological effects in other systems (see Chapter 11) and is listed in modern nutrition books as being a required ultra trace metal. This chapter focuses on vanadium in the biosphere and on naturally occurring compounds or proteins that interact with vanadium or have vanadium in a structural role. Although vanadium concentrations exceeding 350 mmol/L have been reported in the blood cells of ascidians, concentrations of vanadium in mammals are on average in the 10 nmol/L range.
