Selenium supplementation in total parenteral nutrition.

Four adult patients with very low plasma selenium (Se) levels ( less than or equal to 1.5 microgram/100 ml) were given Se supplements while receiving total parenteral nutrition. A comparison was made using the compounds selenomethionine and sodium selenite given either intravenously or by mouth. Urinary excretion and Se plasma responses differed, and indicated that selenomethionine retention was greater. However, the incorporation of Se into the erythrocyte and its enzyme glutathione peroxidase was unpredictable and delayed and was not a good indicator of supplement response. No deleterious effects of supplements were observed. Se supplements are indicated especially in patients with a high risk of developing low Se levels and are best monitored by plasma Se levels.