Biological Trace Element Research

, Volume 54, Issue 3, pp 185–199

Selenium metabolism and bioavailability

  • Lynne A. Daniels
Review

Abstract

Selenium (Se) is at once an essential and toxic nutrient that occurs in both inorganic and organic forms. The biological functions of Se are mediated through at least 13 selenoproteins that contain Se as selenocysteine (Se-cyst). The endogenous synthesis of this amino acid from inorganic Se (selenide Se−2) and serine is encoded by a stop codon UGA in mRNA and involves a unique tRNA. Selenium can also substitute for sulfur in methionine to form an analog, selenomethionine (Se-meth), which is the main form of Se found in food. Animals cannot synthesize Se-meth or distinguish it from methionine and as a result it is nonspecifically incorporated into a wide range of Se-containing proteins. The metabolic fate of Se varies according to the form ingested and the overall Se status of an individual. This paper reviews the bioavailability, including absorption, transport, metabolism, storage, and excretion, of the different forms of exogenous and endogenous Se.

Index Entries

Selenium seleno-cysteine selenoproteins metabolism bioavailability transport review 

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Copyright information

© Humana Press Inc. 1996

Authors and Affiliations

  • Lynne A. Daniels
    • 1
  1. 1.Departments Paediatrics and Child Health and Public HealthFlinders University South AustraliaBedford Park

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