硒的人体最大安全摄入量研究 六、硒的最高界限摄入量和最大安全摄入量

体检349名成年居民结果,发现血硒水平在1.02μg/ml以下者无硒中毒病人,又5名指甲变形长期不能恢复正常者,他们中间最低血浓度为1.054μg/ml(硒日摄入量910μg)。生化检查结果发现当血硒浓度上升到1μg/ml(硒日摄入量850μg)时,凝血酶原时间延长的病例显著上升;此外,在血硒浓度接近0.9μg/ml(硒日摄入量743μg)时,血浆硒/红血球硒的比值下降至低血硒状态时的1/3至1/4。据上述结果,界限日硒摄入量应在750～850μg范围内。考虑到个体差异,建议用2.0作为安全因子,即最高安全摄入量为400μg。又考虑我国高硒区的某些具体情况如居民适应性及环境中某些拮抗元素的存在等,建议在高硒区用1.3作为安全因子,即最高安全摄入量约为每日550μg。

Studies on the Maximum Safe Se Intake of Humans Ⅵ. The Maximum Safe Margin of Daily Se Intake and Maximum Daily Safe Intake of Se

No cases of selenosis had been diagnosed among 349 adult inhabitants as the blood-Se level was below 1.02μg/ml. Furthermore, the minimum blood-Se level to cause persistent finger-nail symptoms among 5 susceptible cases was 1.054μg/ml(daily Se intake 910μg). Biochemical parameters indicate that cases of delay blood prothrombin time distinctly increases as blood-Se level increases to beyond 1μg/ml(daily Se intake 850μg). In addition,plasma-Se to erythrocyte-Se ratio decreases to around 1/3 to 1/4 of that in low blood-Se state as blood-Se level increases to approach 0.9μg/ml(daily Se intake 750μg). Above results indicate the maximum safe margin of daily Se intake should be at a range of 750-850μg. When individual variation is taken into consideration, a maximum daily safe intake of Se is 400μg as a safety factor Of 2.0 is applied For seleniferous area,however, a safety factor 1.3 is applied as other influence factors such as adaptation and environmental antagonistic elements are considered, and the maximum daily safe intake is around 550μg.