ABSTRACT
Vanadium compounds are essential for many cellular functions. Dietary vanadium deficiency leads to disorders of growth, thyroid hormone, lipid and carbohydrate metabolism, and bone mineralization. The estimated daily intake of vanadium is around 10–60 mg. Following oral intake, the highest tissue concentrations are achieved in the kidneys, liver, and lungs; the kidneys remain their principal route of elimination. The biological function of vanadium is highly pH dependent. In a basic solution, it forms orthovanadate (chemically similar to orthophosphates) and enhances phosphorylation reactions by inhibiting phosphatases. Organovanadium compounds improve hyperglycemia, dyslipidemia, and insulin sensitivity in clinical and experimental models of diabetes. We recently identified a small, nontoxic, orally active, insulinomimetic small molecule, 3,5 dimethylpyrazole-peroxy-vanadate (dmp), which not only improves postreceptor insulin sensitivity but also enhances the expression of PPARγ. However, inorganic vanadium compounds can be toxic in supraphysiological doses. Industrial workers exposed to vanadium manifest toxicity involving respiratory, cardiovascular, digestive, renal, central nervous system, and skin. Petroleum and coal-based power industries release significant amounts of vanadium, which not only affects the workers but also the people nearby. Increased urinary excretion of vanadium may serve as a screening tool for individuals at risk of toxicity. Ascorbic acid and dimercaprol have been used successfully to treat vanadium toxicity in humans.
