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Elements, essential ultra trace

Smith HA (1984) Cadmium. In Frieden E, ed. Biochemistry of the Essential Ultra Trace Elements. Plenum Press, New York-London, pp. 341-366. [Pg.340]

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. [Pg.181]

Anke M (1991) The essentiality of ultra trace elements for reproduction and pre- and postnatal development. In Chandra RJ, ed. Trace Elements in Nutrition of Children - II, Nestle Nutrition Workshop Series, Vol 23, Nestec Ltd, Vevey Raven Press Ltd, New York pp. 119—143. [Pg.333]

In order to obtain results that accurately reflect the in vivo distribution of trace element containing species, it is necessary not only to appreciate the limitations of the techniques and methods used but also it is essential to have a thorough understanding of the chemistry of the element and the system under investigation. With the technology presently available, the distribution of various species of some trace elements in a wide variety of samples has been accomplished, however, for other elements this has been difficult if not impossible. Progress in the research of this latter group of elements must await further developments in ultra-trace analytical techniques. [Pg.207]

Elements that do not meet all these criteria, even if there is evidence of positive effects of their presence in a nutritionaUy balanced diet, are not essential. They are referred to as functionally beneficial. Some elements can be found in characteristic quantities in the bodies of all organisms (such as alkali elements, P, S, Cl, Fe, Zn, Cu and Mn) and these are termed invariable elements. Other elements, known as variable elements, occur in higher concentrations only in some organisms. For example, V is present in blood cells of some tunicates, also known as urochordates or in fruiting bodies of some fungi (see Section 6.3.14.2), while in most other organisms it belongs to the trace or ultra trace elements. [Pg.415]

As already mentioned, the ultra trace elements other than selenium and iodine are a disparate group in terms of their possible requirement or nutritional importance for human health and well-being. Although molybdenum has known essential functions, it has no unequivocally identified practical nutritional importance. The other 14 ultratrace elements discussed here have been suggested to be essential based on circumstantial evidence. This evidence is presented below along with some indication of possible requirement (extrapolated from the deficient animal intakes shown in Table 3), and some indication as to what constitutes a high intake. [Pg.403]


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See also in sourсe #XX -- [ Pg.402 ]




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