Selenium levels in whole blood of Finnish volunteers before and during organic and inorganic selenium supplementation

Abstract

High selenium barley biscuits containing 1 μmol (70 μg) organic Se were administered to healthy male volunteers for 5 weeks at doses of 2.1 μmol Se (group A) or 6.4 μmol (group B). In addition, 2 mg Na-selenate capsules (5.4 μmol Se) were given to two other groups at daily doses of 2 mg (group C) or 8 mg (group D). Groups A, B and C each comprised eight healthy men and group D eight healthy women and three men. The initial median concentration of whole blood selenium (B—Se for groups A, B and C were 1.0–1.1 μmol/1 (range 0.7–1.7) and for group D 1.3 μmol/1 (range 0.9–1.8). In 1–2 weeks time the B-Se concentrations rose to 1.6 μmol/1 for groups A and C, to 1.8 μmol/1 for group B, and to 2.2 μmol/1 for group D. There was no decrease 1 week after the Se intake ceased. As expected, the level of B-Se increased more (in relation to dose) in those given organic Se than in those given inorganic Se.

Groups A, B and C, however, had rather moderate increases. The daily dose required to raise the B-Se of Finns up to the North American level (2.2 μmol/1) was as high as 8 mg Na-selenate (21.5 μmol or 1700 μg Se), but the dose of organic Se which would be required to achieve this level is not yet known.

Key-words:

• human nutrition
• selenium
• selenium absorption
• selenium requirements
• selenium supplementation
• sodium selenate
• whole blood selenium