Selenium Flashcards
What oxidations does selenium exist as
+6, +4
What two amino acids create Se analogs
methionine and cysteine
How much of dietary selenium is absorbed
50%
Where in the GI tract is selenium absorbed
duodenum
how is selenium transported
selenocysteine-containing plasma protein
How is selenium excreted
urine (trimethylselenonium) and lungs (very high intake)
What are selenium’s metabolic roles
1) cofactor/constituent of glutathione peroxidase (GSH-px)
2) “water soluble” antioxidant
Selenium deficiency may exacerbate effects of what other deficiency
iodine
what is selenoenzymes, iodothyronine deiodinases, required for
conversion of thyroxine (T4) to active hormone, triiodothyronine (T3)
What are the two deficiency conditions
Keshan disease and Kashin-Beck
Explain Keshan disease
Affects: cardiomyopathy
Type: endemic myocardial disease
Affected population: children and women
Explain Kashin-Beck disease
Affects: joints and bones
Type: endemic deforming disease; rheumatoid condition
Affected population: children, extremely poor
DRI/RDA
55 mcg/day
What food sources contain selenium
organ meats, seafood, muscle meats
Toxicity
> 200 mcg/day for extended time is not recommended
