Vanadium deprivation

Nielsen FH, Uhrigh KE, Shuler TR and Uthus EO (1983) Influence of vanadium deprivation on hematopoiesis and other biochemical parameters. In Anke M. et al., eds. 4. Spurenelement-Sympo-... 

It had been reported earlier (Uthus and Nielsen 1990, Nielsen 1991) that vanadium-deficient nutrition of rats led to increased thyroid weights and thyroid bo-dyweight ratios, and decreased growth. These studies showed that stress factors which alter thyroid status or iodine metabolism also enhance the response to vanadium deprivation. Indeed, it is possible that vanadium is essential in the control not only of certain enzyme reactions but also thyroid metabolism. 

Essentiality. Evidence for the nutritional essentiality of vanadium is not conclusive. Strasia (37) found that rats fed less than 100 ng of vanadium/g of diet exhibited slower growth, higher plasma and bone iron, and higher hematocrits than controls fed 0.5 Mg of vanadium/g of diet. However, Williams (38) was unable to duplicate the findings of Strasia (37), even in the same laboratory under similar conditions. Schwarz and Milne (39) reported that a vanadium supplement of 25 to 50 Mg/100 g of a semi-purified diet gave a positive growth response in rats. On the other hand, Hopkins and Mohr (40) reported that the only effect of vanadium deprivation on rats was an apparent impaired reproductive performcince (decreased fertility and increased perinatal mortality) that became apparent only in the fourth generation. 

I became concerned about the inconsistency of the effect of vanadium deprivation on chicks and rats, and attempted to establish a definite set of signs of vanadium deprivation for these species. In 16 experiments, in which chicks were fed... 

Apparently inconsistency of vanadium deprivation signs is related to the fact that vanadium metabolism is sensitive to changes in the composition of the diet (44). Perhaps diet composition affects the form of dietary vanadium. Vanadium has a rich and varied chemistry, especially in the (IV) and (V) state. The form of vanadium, usually an oxyanlon (i.e. VOa", V02" "), depends upon its concentration in, and pH of, the medium (45). Perhaps, one form is more readily available for absorption, or active in metabolism, than another. Thus, a diet that is relatively low in vanadium might be nutritionally either deficient or adequate depending on the form of the vanadium. 

For iron, iodine, cobalt (as cobalamins), selenium, copper, and zinc there are clinical examples of reversible deficiency disease. For these elements there is enough known about their biochemical functions to explain their importance in human nutrition. For others, such as manganese, chromium, molybdenum, and vanadium, their importance remains to be fuUy accepted in clinical practice. Stfll other elements such as bromine, fluorine, cadmium, lead, strontium, lithium, and tin have been claimed by at least one investigator to be essential for one or more animal species as demonstrated by dietary deprivation studies. 

At least two lines of biochemical evidence support this conclusion. Recently, it was discovered that vanadium is required for the activity of certain enzymes in lower forms of life. These enzymes include nitrogenase in bacteria [39-41] and haloperoxidases in algae and lichens [42-45]. Since thyroid function requires the action of thyroid peroxidase (a haloperoxidase) and thyroid function is essential in growth and development, one can speculate that the deprivation effects of vanadium are mediated via the thyroid gland. 

The quality of the experimental evidence for nutritional essentiality varies widely for the ultratrace elements. The evidence for the essentiality of three elements, iodine, molybdenum and selenium, is substantial and noncontroversial specific biochemical functions have been defined for these elements. The nutritional importance of iodine and selenium are such that they have separate entries in this encyclopedia. Molybdenum, however, is given very little nutritional attention, apparently because a deficiency of this element has not been unequivocally identified in humans other than individuals nourished by total parenteral nutrition or with genetic defects causing disturbances in metabolic pathways involving this element. Specific biochemical functions have not been defined for the other 15 ultratrace elements listed above. Thus, their essentiality is based on circumstantial evidence, which most often is that a dietary deprivation in an animal model results in a suboptimal biological function that is preventable or reversible by an intake of physiological amounts of the element in question. Often the circumstantial evidence includes an identified essential function in a lower form of life, and biochemical actions consistent with a biological role or beneficial action in humans. The circumstantial evidence for essentiality is substantial for arsenic, boron, chromium, nickel, silicon, and vanadium. The evidence for essentiality for the... 

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