Nutrition and Toxicology of Vanadium

Compared to a number of other metals, vanadium appears to be relatively innocuous when ingested in low concentrations by animals however, it is by no means certain that this will be true for chronic exposure, as toxic effects have been reported [80], The nutrition community treats vanadium as a member of the ultra trace metals, which have a nutritional requirement of less than 1 mg/kg diet and are present in tissues in the range of micrograms per kg [81]. Although evidence suggests that vanadium is beneficial to human health, its mechanism of action remains obscure. No specific dietary recommendations have been made, in part, because there is controversy surrounding whether or not vanadium is an essential element. 

Studies in which vanadium was injected into veins of dogs and sheep using 48V as a tracer demonstrated that vanadium was poorly absorbed into the tissues 

To date, there is limited published material concerning the pharmacokinetics of vanadium compounds in humans. The concentration of vanadium in humans not dosed with the metal is extremely low and at the limits of detection of many of the analytical techniques used. It is not possible to ascertain if the large differences observed in different populations are the result of environmental exposure or experimental variability. Studies using blood have shown vanadium levels of 0.4 to 2.8 pg/L in normal people. The serum contains the largest amount of vanadium with concentration values ranging from 2 to 4 pg/L using atomic absorption spectroscopy [90], The upper limit of vanadium in the urine of normal people was reported to be 22 pg/L, with excretion values averaging below 8 pg/24 h. Vanadium is widely available in nutrition stores for athletes, who believe it to be a nonsteroidal compound that increases muscle mass at a dose of approximately 7 to 10 mg day, without any reports of toxicity [91]. 

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