Indicators of Selenium Status

Early animal studies and human population surveys used whole blood as the main indicator of selenium status. Whole blood selenium can be determined after acid digestion using a fluorometric method. The more convenient carbon furnace atomic absorption spectroscopy (CFAAS) assay for plasma and/or serum selenium is now the most widely used procedure. The main components of plasma selenium are extracellular glutathione peroxidase (GSHPx 3) and selenoprotein P. 

Huang W, Akesson B, Svensson BG. 1995. Selenoprotein P and glutathione peroxidase (EC 1.11.1.9) in plasma as indices of selenium status in relation to the intake of fish. Br J Nutr 73 455-461. 

Portal B, Richard MJ, Ducros V, et al. 1993. Effect of double-blind crossover selenium supplementation on biological indices of selenium status in cystic fibrosis patients. Clin Chem 39(6) 1023-1028. 

Ullrey DE. 1987. Biochemical and physiological indicators of selenium status in animals. J Anim Sci 65 1712-1726. 

Navarro-Alarcon M, Lopez-G de la Serrana H, Perez-Valero V, et al. 1999. Serum and urine selenium concentrations as indicators of body status in patients with diabetes mellitus. Sci Total Environ 228 79-85. 

The selenium levels of blood and blood components are widely used as indicators of Se status in humans, since they are sensitive to dietary intake and can therefore complement such studies and give an indication of amounts absorbed fixim the diet. A significant correlation was found between dietary Se intake and whole-blood selenium [57]. 

Hawkes, W.C., C.C. Willhite, K.A. Craig, S.T. Omaye, D.N. Cox, W.N. Choy, and A.G. Hendrickx. 1992. Effects of excess selenomethionine on selenium status indicators in pregnant long-tailed macaques (Macaca fascicularis). Biol. Trace Elem. Res. 35 281-297. 

Hojo Y. 1982. Single-void urine selenium level expressed in terms of creatinine content as an effective and convenient indicator of human selenium status. Bull Environ Contam Toxicol 29 37-42. 

McMaster D, Bell N, Anderson P, et al. 1990. Automated measurement of two indicators of human selenium status, and applicability to population studies. Clin Chem 36(2) 211-216. 

Blood selenium levels have been widely used as indices of dietary selenium intake and selenium status in both animals and humans (Levander 1972, 1982, 1986,... 

DEFICIENCY SYMPTOMS. There are no clear-cut signs or symptoms which indicate when people are mildly to moderately deficient in selenium. However, many tests on diverse species of animals and man have shown that blood and tissue levels of selenium are in most cases accurate reflections of the selenium nutritional status. But the interpretation of laboratory findings and the diagnosis of selenium deficiency are strictly jobs for health professionals, even though certain laboratories may analyze specimens for lay persons. Henc e, the information which follows is presented so that the patient and his or her doctor might consider whether such tests are advisable. 

The selenium data are presented in Chapter 111 and Appendix E. Unless otherwise indicated, they refer to standard conditions cf. Section 11.3) and 298.15K (25°C) and are provided with an uncertainty which should correspond to the 95% confidence level (see Appendix C). Thermodynamic parameters (formation data and entropies) that could be evaluated from reaction data with selected TDB auxiliary data in Chapter IV are denoted as selected and presented in Chapter III. When use of non-TDB auxiliary data had to be resorted to in the evaluation, the result is denoted as adopted and presented in Appendix E. The difference in the status between a selected and an adopted value thus depends entirely on the background of the auxiliary data used in the assessment. 

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