Objective: The purpose of this study was to evaluate the pharmacokinetics of a single dose of Selenium (Se) from yeast given to humans with a habitual long-term daily intake at a supra-nutritional level.
Methods: Twelve healthy males with a daily supplemental intake of 300 microg Se as selenised yeast over 10 weeks were supplemented with a single dose of 327 microg as stable (77)Se incorporated into selenised yeast manufactured by the same standardised process (SelenoPrecise(R), Pharma Nord, Denmark).
Results: Absorption of Se from (77)Se-enriched yeast was 89+/-4% and the retention was 74+/-6%. The (77)Se excretion from the single-dose was 47+/-15 microg in urine and 37+/-13 microg in faeces. The maximum, enriched (77)Se concentration in plasma was 9.8+/-1.5 microg/l and the time to maximum was 9.2 hours. The plasma halftime of (77)Se was longer with increasing time; 1.7 days for the initial phase ((1/2)-2 days), 3.0 days for the middle phase (2-3 days) and 11.1 days for the later phase (3-14 days).
Conclusion: The Se from the standardised Se-enriched yeast was well absorbed and retained in the body.
Keywords: absorption; excretion; humans; pharmacokinetics; selenium yeast; stable isotope.