Vanadium--an element of atypical biological significance.

The biological image of the transition element vanadium ferments a great deal of contradiction-from toxicity to essentiality. Importance of this element as micro-nutrient is yet to be unequivocally accepted by biologists and biomedical scientists. In spite of toxicity, it seems interesting to analyze the different biological roles of the element. Vanadium compounds have been proven to be associated with various implications in the pathogenesis of some human diseases and also in maintaining normal body functions. Salts of vanadium interfere with an essential array of enzymatic systems such as different ATPases, protein kinases, ribonucleases and phosphatases. While vanadium deficiency accounts for several physiological malfunctionings including thyroid, glucose and lipid metabolism, etc., several genes are regulated by this element or by its compounds, which include genes for tumor necrosis factor-alpha (TNF-alpha), Interleukin-8 (IL-8), activator protein-1 (AP-1), ras, c-raf-1, mitogen activated protein kinase (MAPK), p53, nuclear factors-kappaB, etc. All these seem to be not far from its recognition as an element of pharmacological and nutritional significance, which is revealed through its increasing therapeutic uses in diabetes. Vanadium is also emerging as a potent anti-carcinogenic agent. This review summarizes the developments related to vanadium biology as a whole by analyzing the general biochemical functions of vanadium.

Deliberations and evaluations of the approaches, endpoints and paradigms for dietary recommendations of the other trace elements.

Circumstantial evidence suggests that aluminum, arsenic, bromine, cadmium, germanium, lead, lithium, nickel, rubidium, silicon, tin and vanadium are essential. The evidence is most compelling for arsenic, nickel, silicon and vanadium. The estimated daily dietary intakes for these elements are arsenic, 12-50 micrograms; nickel, 100 micrograms; silicon, 20-50 mg and vanadium, 10-20 micrograms. By extrapolation from animal studies, the daily dietary intakes of these elements needed to prevent deficiency or to provide beneficial action in humans are arsenic, 12-25 micrograms; nickel, 100 micrograms; silicon, 2-5 mg (based on 10% bioavailability in natural diets) and vanadium, 10 micrograms. Thus, the postulated need by humans for these elements can be met by typical diets. Because there may be situations, however, where dietary intake does not meet the postulated requirements, research is needed to derive status indicators in humans and to further study the relationships of low intake or impaired bioavailability of these ultratrace elements to various diseases.

[Vanadium, an indispensable trace element in living organisms. Current data on biochemical, metabolic levels and therapeutic doses]. / Il vanadio, oligoelemento indispensabile per gli organismi viventi. Recenti acquisizioni a livello biochimico, metabolico e terapeutico.

Having briefly analyzed the role of vanadium in living organisms, the author describes conditions induced by vanadium poisoning and deficit. The most recent acquisitions concerning the use of vanadium in the treatment of diabetes mellitus and its consequent role in the prevention of atherosclerosis are also illustrated.

The importance of diet composition in ultratrace element research.

This review indicates that the lack of appreciation of, information about or understanding of the importance of diet composition has had a major influence on the development of knowledge about 11 ultratrace elements in nutrition. Inappropriate trace element supplementation and inadequate or unbalanced diets probably were responsible for many of the reported inconsistent and divergent findings, and thus, for the resultant controversy regarding the essentiality of specific ultratrace elements. Vanadium and nickel are taken as examples, and evidence is presented that variations in the concentrations of dietary components can affect the response of experimental animals to the various ultratrace elements. Furthermore, there is evidence that the ultratrace elements, given in sufficient quantity, can evoke pharmacological responses in animals. Failure to recognize these phenomena probably has led to a number of incorrect or biased interpretations of experimental results. Future research on the importance of ultratrace elements in nutrition requires close attention to an often neglected experimental variable--diet composition.