Trace Elements

Question 1

Is RDA for iron in women between 19-50 taking oral contraceptives lower or higher

Answer 1

Lower

Question 2

Is the RDA for iron in women 51+ higher or lower

Answer 2

Lower

Question 3

what food products are good sources of iron?

Answer 3

meat and fish, leafy greens, lentils and whole grains
- cooking with iron utensils adds iron to food

Question 4

why do vegetarians/vegans require more dietary iron?

Answer 4

because the iron in plant foods is more difficult to absorb

Question 5

iron that is part of which group is better absorbed?

Answer 5

heme-group

Question 6

what food is heme-iron found in?

Answer 6

meat (hemoglobin in blood and myoglobin in muscle)

Question 7

what is non-heme iron?

Answer 7

any dietary iron that is not bound to the heme group (e.g. plant-based iron).
- This is more difficult to absorb

Question 8

iron is absorbed in which form?

Answer 8

directly in its Fe2+ (ferrous) form or as Heme-bound iron
- easier to absorb

Question 9

what can enhance the absorption of iron?

Answer 9

Acidic foods, stomach acid and Vitamin C

Question 10

what can prevent absorption of iron?

Answer 10

Fibre, phytates, tannins and oxalates can bind iron and prevent its absorption
- as well as other minerals (calcium)

Question 11

how is iron stored?

Answer 11

stored as part of the protein Ferritin in:
- Mucosal Cells
- Liver

Question 12

how is iron transported?

Answer 12

transported as part of the protein Transferrin
- Body cells for use like myoglobin
- Bone marrow for production of RBCs
- RBCs as hemoglobin for transport of O2
- Liver for storage as Ferritin
- RBCs are recycled in the spleen, marrow and liver, allowing the iron to be reused

Question 13

when can iron be lost?

Answer 13

• When mucosal cells containing ferritin die
• When blood is lost, results in loss of transferrin and hemoglobin in RBCs

Question 14

what is iron used for in the body?

Answer 14

• Hemoglobin – delivery of O2 and removal of CO2
• Myoglobin – storage of O2 in muscle cells
• Citric Acid Cycle and Electron Transport Chain Proteins
• Drug Metabolism – Cytochrome P450 (contains a Heme group)
• Immune Function
• Catalase – Protein that protects from oxidative stress by converting H2O2to water and oxygen

Question 15

does iron deficiency happen fast or slow?

Answer 15

slow

Question 16

what are common symptoms of iron deficiency?

Answer 16

fatigue, weakness, headache, decreased work capacity, an inability to maintain body temperature in a cold environment, changes in behavior, decreased resistance to infection, adverse pregnancy outcomes, impaired development in infants, and an increased risk of lead poisoning in young children, [pica]

Question 17

what’s the normal range for hematocrit for men and women?

Answer 17

men: 0.420-0.520
women: 0.370-0.460

Question 18

what’s the normal range for hemoglobin for men and women?

Answer 18

men: 140g/L
women: 123-157 g/L

Question 19

what’s the normal range for serum iron?

Answer 19

11-32 umol/L

Question 20

what’s the normal range for ferritin?

Answer 20

10-250 ug/L

Question 21

iron toxicity leads to what?

Answer 21

increased oxidative stress

Question 22

what is one of the most common forms of poisoning children?

Answer 22

iron toxicity - ACUTE

Question 23

what is chronic iron toxicity?

Answer 23

Iron Overload or hemochromatosis
- Increased iron absorption

Question 24

what are forms of iron supplementation?

Answer 24

• Iron cookware and utensils
• Iron consumed with acidic foods and foods with vitamin C (e.g. orange juice) is more readily absorbed

Question 25

why should dairy consumption be avoided when aiming to increase iron intake?

Answer 25

calcium, Ca2+ can interfere with absorption

Question 26

Iron supplements can interfere with intake of which trace elements?

Answer 26

Copper and Zinc

Question 27

zinc from what sources is better absorbed?

Answer 27

meat

Question 28

what can prevent the absorption of zinc?

Answer 28

Phytates in vegetables can bind zinc and prevent its absorption

Question 29

what is zinc lost in?

Answer 29

lost in grain processing and not added back as enrichment

Question 30

what do Zinc transport proteins regulate?

Answer 30

the amount of zinc absorbed in the small intestine

Question 31

what does Metallothionein proteins regulate?

Answer 31

the amount of zinc that moves into the blood from the mucosal cells

Question 32

how is zinc excreted?

Answer 32

in the pancreatic and intestinal juices, allowing excess zinc to be removed from the body

Question 33

copper absorption is highly impacted by which trace element?

Answer 33

zinc high zinc = low copper

Question 34

what food products are good sources of copper?

Answer 34

Organ meats, seafood, nuts and seeds, whole grains - Soil content will impact levels in food

Question 35

Free copper can lead to what?

Answer 35

oxidative damage, so transported in the blood with albumin

Question 36

where is copper secreted?

Answer 36

in the bile, allowing it to be excreted in the feces

Question 37

copper is important in the transport of which element?

Answer 37

iron

Question 38

what can prevent oxidative stress with copper?

Answer 38

Superoxide dismutase

Question 39

Deficiency is rare in copper but symptoms include:

Answer 39

- anemia (poor iron transport) and - connective tissue defects (similar to scurvy due to its role in collagen cross-linking)

Question 40

what food products are the best sources of manganese?

Answer 40

whole grains and nuts

Question 41

how is manganese eliminated?

Answer 41

in bile

Question 42

Manganese-requiring enzymes are involved in what?

Answer 42

amino acid, carbohydrate, and cholesterol metabolism, cartilage formation, urea synthesis, and antioxidant protection

Question 43

manganese is a part of mitochondrial superoxide dismutase. t or f

Answer 43

t

Question 44

what food products are good sources of selenium?

Answer 44

Seafood, animal products, and whole grains (depending on soil content)

Question 45

is absorption regulated in selenium?

Answer 45

no, excess selenium is excreted in the urine

Question 46

selenium is a part of selenoproteins (proteins with selenium). t or f

Answer 46

t Glutathione peroxidase is an example Protects from oxidative stress by neutralizing peroxides

Question 47

selenium is needed for the synthesis of which hormone?

Answer 47

thyroid hormones

Question 48

what does a deficiency in selenium look like?

Answer 48

- Muscular discomfort and weakness - Keshen disease Enlarged heart and poor heart function

Question 49

what does selenium toxicity look like?

Answer 49

Changes in fingernail structure and hair loss

Question 50

where is iodine found in?

Answer 50

sea water

Question 51

is the RDA for iodine high or low during pregnancy and lactation?

Answer 51

higher

Question 52

what food products are a good source of iodine?

Answer 52

- Seafood and plants grown near the sea would be high in iodine - Plants grown far from the sea have low iodine in their soil - Can also make it into our food from additives in cattle feed and disinfectants that contain iodine

Question 53

Salt sold for household use must be fortified with what?

Answer 53

iodine (iodized salt)

Question 54

iodine is used in the synthesis of what hormone?

Answer 54

thyroid hormone - Thyroid hormones are synthesized from the amino acid tyrosine

Question 55

where is fluoride present?

Answer 55

in low amount in almost all soil, water, plants and animals

Question 56

what food product is a good source of fluoride?

Answer 56

tea

Question 57

In the body, fluoride associates with calcium and helps protect what?

Answer 57

protect teeth from cavities by making the enamel more resistant to acids

Question 58

deficiency in fluoride can increase the risk of what?

Answer 58

tooth decay

Question 59

high doses of fluoride can lead to what?

Answer 59

fluorosis

Question 60

When do symptoms occur from iron deficiency?

Answer 60

When it reaches iron deficiency anemia

Question 61

Tx for iron toxicity

Answer 61

Replacing blood, or removing blood from the body

Question 62

The more zinc you consume, doesn’t mean it’s gonna get into the blood. T or F

Answer 62

T

Question 63

Zinc is a cofactors for over 300 enzymes, and helps reduce

Answer 63

Oxidative stress as a cofactor in superoxide dismutase

Question 64

Zinc in DNA binding proteins

Answer 64

Many hormones bind to proteins w zinc fingers, meaning deficiency can have widespread effects on the body

Question 65

Zinc deficiency usually occurs in those with

Answer 65

A mutation in a zinc transporter Those consuming diets low in protein or high in phytates

Question 66

Cause of copper toxicity

Answer 66

due to contaminated water supplies or water/food stored in copper

Question 67

How is absorption inversely associated with intake of manganese

Answer 67

More you intake, less you absorb

Question 68

Is the RDA for iodine in pregnancy and lactation higher or lower

Answer 68

Higher

Question 69

Iodine can make it into our food from additives in

Answer 69

Cattle feed an disinfectants that contain iodine

Question 70

Synthesis of thyroid hormone from iodine regulate gene expression of proteins involved in:

Answer 70

Protein synthesis Basal metabolic rate Growth and development

Question 71

Thyroid stimulated hormone (TSH) in Iodine

Answer 71

Released when hormone levels drop Causes thyroid hormone to synthesis more, enlarging it and taking it more iodine

Question 72

What leads to enlargement of the thyroid gland with iodine deficiency

Answer 72

Iodine deficiency means no thyroid hormones are being made and TSH keeps getting released , leading to enlargement of the thyroid gland

Question 73

Iodine deficiency leads to the development of

Answer 73

Goiter

Question 74

Iodine hormones are needed for growth and development in

Answer 74

Pregnancy and lactation

Question 75

What can happen if iodine is deficient in pregnancy and lactation

Answer 75

Still birth, abortion, cretinism in children

Question 76

What are goitrogens

Answer 76

Substances in food that limits iodine bioavailability (cabbage, cassava, millet)