Results obtained from previous studies shoved that at low level of dietary selenium(0.03 ppm) weanling rats fed with diets of low protein level usually possessed higher selenium concentration and GSHPx activity in their blood and tissues. The results were reproduced in chickens in this observation. Furthermore, even the original selenium level could not be maintained in blood and tissues of chickens fed with low protein diet (12.4%) because of faster growth rate and the lower selenium content (0.01 ppm) of the diet used in this study.Of the 27 chickens consuming 18.2% protein diet in the 14 days expe- riment, 23 suffered from exudative diathesis and 3 died without any sign of exudative diathesis, while in the 12.4% protein group only one of the 26 chickens suffered from exudative diathesis during the 14 days experiment and 6 of the 12 chickens in this group observed for another two weeks showed exudative diathesis. In the 18.2% protein group the first chicken with signs of exudative diathesis appeared on the 9th day while it appeared on the 14th day in the 12.4% protein group.How to improve the selenium nutritional status of the residents in Ke-shan Disease areas was discussed.

The weaning male Wistar rats were fed diets with 0.2, 2.0 and 5.0 ppm as Na2SeO4 respectively for 7 weeks. On each Se level, rats were divided into groups with or without supplementation of vitamin E and DL-methi-onine (VE-Met) and possible metabolic interactions of VE-Met to dietary Se at different levels in relation to the detoxification mechanism were ob- served. The results showed that only rats in unsupplemented, 5 ppm Se-diet group exhibited distinct toxic manifestations, and supplementation of VE-Met to this group gave effective protection against the toxic action. In the supplemented group Se content of blood, liver, kidneys and skeletal muscle of the experimental animals was decreased, while the excretory rate of urinary trimethylselenonium ion was increased to a level of 33% in contrast to 22% in the unsupplemented group (P

The average daily selenium intake of staff of the Institute of Health in Beijng was surveyed to be 66.4?g and that of children in nursery and kindergarten was 34.7?g, which could meet the Recommended Dietary Allowance as suggested. Cereals were the major source of dietary selenium which accounted for 63.6% of total dietary intake, and animal and plant foods provided about 25.9% and 10.5% respectively. Both cereals and animal foods were the major sources of selenium in children diet, which accounted for 48.9% and 44.3% respectively, and intake of selenium from other sources was negligible.The selenium concentrations in whole blood and hair of the population were 0.146ppm and 0.578ppm respectively, and both correlated well with the daily selenium intake.The daily intake of mercury, arsenic, and cadmium for population in Beijing were estimated to be 3.4, 52.7, and 42.7*g respectively, which were within the normal range of intake and would not significantly interfere with the bioavailability of selenium ingested. It was suggested thal these levels of selenium daily intake surveyed would be adequate for human consumption and could be helpful as a reference for the establishment of dietary allowance.

The content of selenium and several antagonistic metals such as mercury, arsenic, and cadmium in foods from Beijing market has been determined. Results showed that marine products, Viscera (particularly kidney), eggs, and mushroom were good dietary sources of selenium. The selenium contents of imported cereals and pulse are much higher than those grown in China as far as the sample analysed. Most vegetables and fruits contained selenium below a level of 0.010ppm with exception of garlic and mushroom.The selenium content of human milk was higher than other kinds of milk, milk products and milk-substitutes. Selenium content of Beijing foods was far higher than those in affected area of Keshan disease. The mercury, arsenic, and cadmium content of foods was below the National Allowance Standard except a few marine products.The selenium content of natural plant foods was positively correlated with its protein content (r=0.844, p