On supplementing the selenium intake of New Zealanders

Abstract

1. Urinary and faecal excretion of single oral doses of 1 mg selenium or 0.1 mg Se as selenomethionine (Semet-Se) in solution were studied in two women. Most of the Se was absorbed and little was eliminated in the urine (0.05–0.22 dose).2. The results have been compared with those from an earlier study (Thomson, 1974) on the same two women after similarly sized doses of sodium selenite (selenite-Se) in solution. Although selenite-Se was almost as well absorbed as Semet-Se more was excreted in the urine (0.41–0.85 dose).3. Repeated dosing with 1 mg selenite-Se on five consecutive days in one of the women indicated that 1.1 mg had been retained.4. Twenty patients with muscular complaints from Tapanui (South Otago, New Zealand), a low-Se soil area, ingested 0.5 mg selenite-Se daily for 20 d. Blood Se increased rapidly to almost twice the initial concentration but reached a plateau well below most values reported for residents outside New Zealand. No difference in blood Se concentration was found between those who did or did not report improvement.5. Spasmodic medication with selenite-Se by some residents near Lincoln (Christchurch, New Zealand) for periods of up to 10 years or more had increased the blood Se somewhat.