9 Microminerals Flashcards
What are the most important dietary sources of zinc?
Animal product (red meat, oysters).
What major functions does zinc have?
Component of enzymes, maintenance of structural integrity of proteins, regulation of gene expression.
Important for growth and development, immune response, neurological function, reproduction, apoptosis, regulation of gene expression.
What is the EAR for zinc based on?
Minimal quantity of absorbed Zn to replace to endogenous losses.
Are endogenous zinc losses the same for men and women?
Men have additional loss through semen. There is no compensatory absorption, so must increase consumption.
Do zinc requirements increase during pregnancy? Why or why not?
Increased metabolic need, so higher requirements.
What are iodines main functions?
Essential component of thyroid hormones.
When does iodine deficiency have the highest risk to the fetus? What can it cause?
First trimester. Associated with increase incidence of miscarriage, still birth, and cretinism.
What is the key role of iodine specifically for fetal development?
Important for myelination of the CNS.
Do iodine requirements change during pregnancy? Why or why not?
Yes increases, due to the daily thyroid iodine take up by the fetus.
What is seleniums major function?
Assimilated into selenoproteins which participate in oxidant defence (GPxs). Critical for normal development, growth, and metabolism through the regulation of thyroid hormones since Se dependent iodothyronine deiodinase enzymes are the ones that convert inactive T4 to active T3
What is the EAR for selenium based on?
Based on intakes that would maximize glutathione peroxiases (GPxs).
What is Keshan disease?
Cardiomyopathy in children see in Se deficient areas. See acute/chronic episodes of cardiogenic shock and/or congestive heart failure.
Does the RDA for selenium change during pregnancy? Why or why not?
It increases because there needs to be enough selenium for the fetus to saturate it’s selenoproteins
What are the main functions of copper?
Metaloenzyme oxidase component. MAO (serotonin degradation), diamine oxidase (inactivate histamine), Lysyl oxidase (connective tissue development).
How is the EAR for copper determined?
Factorial method: determine obligatory losses and calculate amount needed to replace. Looked at activity and when indicators decreased over time, must be in deficient range.
