Trace Elements

Question 1

Where is iron found in the diet?

Answer 1

Lentils
Seafood
Meat
Spinach (cooked)
Eggs
Seeds
Nuts

Question 2

How is iron absorbed and stored?

Answer 2

Absorbed in intestines
Heme iron absorbed and converted to ferric form by copper containig protein in mucosal cells
Iron is then stored by binding to ferritin however this form is excreted when the cell dies

Question 3

Is it possible to lose iron from the body?

Answer 3

Only way to lose iron is through blood loss

When RBC break down, iron is resorbed and used to make more hemoglobin

Question 4

What is the function of Iron? (4)

Answer 4

Component of myoglobin and hemoglobin
Part of proteins in CAC &ETC along with transport for O2 and CO2
Implicated in energy generation
Has immune functions

Question 5

Who is at most risk for iron deficiency?

Answer 5

Children and women
Women due to menstruation
Children due to increased needs during growth

Question 6

What is hemochromatosis?

Answer 6

Iron overload which causes oxidative damage eventually leading to chronic diseases and premature death

Question 7

Where is zinc found in diet?

Answer 7

Available in meats and vegetables

Less easily absorbed from plants due to binding by phytates

Question 8

How does high levels of zinc affect bioavailability of other minerals?

Answer 8

Metallothionein is used to bind to zinc to control transfer into blood
However copper also binds to metallo
Thus too much zinc means inhibition of copper absorption

Question 9

What is the function of Zinc?

Answer 9

Allows regulation of DNA transcription
Involved in insulin storage and release
Zinc fingers allow certain hormones to regulate gene expression

Question 10

How can we increase absorption of copper when there are high levels of zinc in our body?

Answer 10

Phytates bind to zinc

Allows copper to inc its absorption

Question 11

How does copper have an effect on anemia?

Answer 11

Copper deficiencies can lead to anemia
D/t copper-containing proteins are required for iron transport in body
No copper = no iron being transported = anemia

Question 12

What is manganese used for?

Answer 12

Part of superoxide dismutase in mitochondria

Required for enzymes resp for AA, carb and chol metabolism

Question 13

How is manganese eliminated?

Answer 13

Elimination through bile

Question 14

What is the function of selenium?

Answer 14

Part of glutathione peroxidase

Red the prod of free radicals

Question 15

What are the signs of selenium deficiency?

Answer 15

Muscle weakness
Discomfort
Poor heart function

Question 16

What is the function of iodine?

Answer 16

Component of thyroid hormones thyroxine (T4) and triiodothyronine (T3)
Thyroid hormones reg protein synthesis, basal metabolic rate and growth/dev by controlling gene exp

Question 17

How is low levels of thyroid hormone regulated?

Answer 17

Thyroid hormones controlled by release of thyroid-stimulation hormone from pit gland when levels are low
TSH causes thyroid gland to take up iodine and synth hormones

Question 18

Why is iodine important to growth and development?

Answer 18

Iodine is essential for synthesis of thyroid hormones

Question 19

What are the symptoms of iodine deficiency?

Answer 19

Reduced metabolic rate
Fatigue
Weight gain
Goiter