Selenium Flashcards
1
Q
How is selenium absorbed?
A
Selenium is bound to cysteine or methionine in food
- selenomethionine
- selenocystine
Is absorbed bound to these amino acids
50-100% of intake is absorbed
phytates and mercury interfere
Vitamins A, C, E help
2
Q
What is the biologically active form?
A
Selenocysteine
Used to synthesise glutathione peroxidase
3
Q
How and where is selenium stored in the body?
A
Stored as selenomethionine
Liver, pancreas, muscle, kidneys
4
Q
What is the function of selenium?
A
- part of the antioxidant defence system as a cofactor of glutathione peroxidase: prevents peroxidation and spared vitamin E
- thyroid hormone metabolism: cofactor to DIOs which converts T4 to T3
5
Q
What is the result of a selenium deficiency?
A
- decreased levels of circulating T4
- Keshan’s disease which causes enlarged heart, CVD and higher rates of cancer (not causational)
6
Q
What is caused by selenium deficiency?
A
- garlic breath
- nausea
- diarrhoea
7
Q
What are good sources of selenium?
A
- oysters, sardines
- steak
- chicken
