Selenium speciation in human body fluids†

Abstract

Selenium consumed by humans in foods and in supplements exists in a number of different organic and inorganic forms including selenomethionine, selenocysteine, selenate and selenite. Animal and human studies have established that the bioavailability of the selenium depends upon the chemical form, which also influences the distribution of selenium in the body. These studies have included urinary excretion of selenium following ingestion of different forms of selenium and the response of tissue selenium concentrations and activities of functional selenoproteins to these selenium compounds. Selenomethionine is retained in tissue proteins to a greater extent than selenocysteine and the inorganic forms, but the selenium is not necessarily immediately available for functional selenoproteins. A number of other factors besides chemical form may also influence the bioavailability and distribution of selenium, including other dietary components, selenium status, physiological status and species. Knowledge of these factors and of speciation of selenium in foods, tissues and functional selenoproteins is important for the accurate assessment of selenium status. Speciation of selenium also has implications with respect to the determination of selenium requirements and to the investigation of relationships between selenium status and health and disease.

Selenium and Selenoprotein P1 Levels Are Related to Primary Open-Angle Glaucoma / Nivoi Selena I Selenoproteina P1 Povezani Su Sa Primarnim Glaukomom Otvorenog Ugla

“…In agreement with other studies (19,20), which showed maximum GPx1 activity occurrs with selenium values higher than 100 ng/mL, we found that the serum selenium concentrations were higher than 213 ng/mL.…”

Selenium content of Spanish infant formulae and human milk: Influence of protein matrix, interactions with other trace elements and estimation of dietary intake by infants

“…The need to provide infant formulae which satisfy the dietary requirement for selenium just as human milk is doing, should prompt further speciation studies (51,52) …”

Assessment of requirements for selenium and adequacy of selenium status: a review

“…Daily urinary excretion is closely associated with plasma selenium and dietary intake in low selenium populations (Griffiths & Thomson, 1974), and, therefore, can be used to assess selenium status reflecting recent dietary intake. Balance studies show that over a wide range of intakes, urinary excretion accounts for 50-60% of the total amount excreted (Robinson et al, 1973), and therefore, total dietary intake can be estimated as twice the daily urinary excretion (Thomson, 1998).…”