Abstract
The recent Expert Consultation of World Health Organization (WHO)/Food and Agricultural Organization (FAO)/International Atomic Energy Agency (IAEA) defined essentiality of a trace element as follows: “An element is considered essential to an organism when reduction of its exposure below a certain limit results consistently in a reduction in a physiologically important function, or when the element is an integral part of an organic structure performing a vital function in the organism.” This definition omits a previous postulate that the mechanism of action of an essential trace element should be well defined; it also supersedes another criterion, once suggested for essentiality, a normal, rather than log-normal distribution of an element’s tissue concentrations. The Expert Consultation offers no generally applicable criteria for the physiological importance of functions, and that determination is left to expert groups charged with setting national and other nutritional recommendations. The use of the term “physiological” rather than “biochemical” strongly implies that neither changes of an element’s concentration nor of a specific enzyme function alone are proof of essentiality. Among physiologically important functions are growth, reproduction, longevity, and all metabolic and hormonal functions that bear a clear, inverse relation to disease risk. Finally, the term “consistent” states the need for independent confirmation of the original data, before an element can be recognized as essential. These definitions will be discussed as background for further discussions of our present knowledge of boron (B).
Similar content being viewed by others
References
D. A. Richert and W. W. Westerfeld, Isolation and identification of the xanthine oxidase factor as molybdenum,J. Biol. Chem. 203, 915–923 (1953).
E. C. DeRenzo, E. Kaleita, P. Heytler, J. J. Oleson, B. L. Hutchings, and J. H. Williams,Arch. Biochem. Biophys. 45, 247 (1953).
K. V. Rajagopalan, Molybdenum: an essential trace mineral in human nutrition,Ann. Rev. Nutr. 8, 401–427 (1988).
M. Anke, B. Groppel, and M. Grün, Essentiality, toxicity, requirement and supply of molybdenum in human and animals, inTrace Elements in Man and Animals TEMA 5, C. F. Mills, I. Bremmer, and J. K. Chesters, eds., Commonwealth Agricultural Bureaux, Farnham Royal, UK pp. 154–157 (1985).
K. Schwarz and C. M. Foltz, Selenium as an integral part of factor 3 against dietary necrotic liver degeneration,J. Am. Chem. Soc. 79, 3292–3293.
K. Schwarz and W. Mertz, Chromium(III) and the glucose tolerance factor,Arch. Biochem. Biophys. 85, 292–295 (1959).
W. Mertz, E. E. Roginski, and K. Schwarz, Effect of trivalent chromium complexes on glucose uptake by epididymal fat tissue of rats,J. Biol. Chem. 236, 318–322 (1961).
W. Mertz, Some aspects of nutritional trace element research,Fed. Proc. 29, 1482–1488 (1970).
Expert Consultation WHO/FAO/IAEA, Trace elements in human nutrition and health. WHO, Geneva, pp. 343 (1996).
H. A. Schroeder, Chromium deficiency in rats: A syndromelating diabetes mellitus with retarded growth,J. Nutr. 88, 439–445 (1966).
J. C. Smith and K. Schwarz, A controlled environment system for new trace element deficiencies,J. Nutr. 93, 182–188 (1967).
A. I. Venchikow, On physiologically active quantities of a microelement and the mechanism governing manifestations of their effect,Vopr. Pitaniya. 6, 3–11 (1960).
Committee on Dietary Allowances, Recommended Dietary Allowances, 9th ed.,Nail. Acad. Sci. Washington, DC, pp. 185 (1980).
G. F. Nordberg and S. Skerfvening, Editors’ comments,Scand. J. Work, Environ. Health 19 (Suppl. 1), 138 (1993).
W. Mertz, Metabolism and metabolic effects of trace elements, inTrace Elements in Nutrition of Children, R. J. Chandra, ed., Raven, New York, pp. 107–117 (1985).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Mertz, W. Review of the scientific basis for establishing the essentiality of trace elements. Biol Trace Elem Res 66, 185–191 (1998). https://doi.org/10.1007/BF02783137
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF02783137