代谢
大部分膳食硒以硒代甲硫氨酸(硒的主要膳食形式)或硒代半胱氨酸的形式存在,这两种形式都能很好地被吸收。其他形式的硒包括硒酸盐和亚硒酸盐,它们不是膳食的主要成分,但常用于强化食品和膳食补充剂中。人体内存在两种储备硒池。第一种是硒代甲硫氨酸,它除了具有甲硫氨酸的生理功能外,没有已知的独立生理功能。第二个储备池是存在于肝脏谷胱甘肽过氧化物酶中的硒。摄入的亚硒酸盐、硒酸盐和硒代半胱氨酸都直接代谢为硒化物,即硒的还原形式。硒代甲硫氨酸也可以代谢为硒化物。/硒酸盐/
Most dietary selenium is in the form of selenomethionine (the major dietary form of selenium) or selenocysteine, both of which are well absorbed. Other forms of selenium include selenate and selenite, which are not major dietary constituents, but are commonly used in fortified foods and dietary supplements. Two pools of reserve selenium are present in the body. The first is as selenomethionine, which is not known to have a physiological function separate from that of methionine. The second reserve pool is the selenium found in liver glutathione peroxidase. Ingested selenite, selenate, and selenocysteine are all metabolized directly to selenide, the reduced form of selenium. Selenomethionine can also be metabolized to selenide. /Selenate/
来源:Hazardous Substances Data Bank (HSDB)