The metabolism of [75Se]selenomethionine in four women.

1. The long-term fate of an oral dose [75Se]selenomethionine was studied in four women. 2. Urinary and faecal excretion, respiratory losses and whole-body retention of 75Se were measured, and also 75Se turnover in whole body, plasma and erythrocyte during a period of 33-34 weeks. 3. Intestinal absorption of [75Se]selenomethionine by the four subjects was 95.5-97.3% of the administered dose. 4. Urinary excretion accounted for 6-9% of absorbed 75Se in the first 2 weeks. No radioactivity was detected in expired air.