Chapter 13

Question 1

Definition

The Trace Minerals

Answer 1

Microminerals needed in amounts <100 mg/day.

Question 2

Functions

The Trace Minerals

Answer 2

Active in digestion, circulation, movement, and nervous system.

Question 3

Sources

The Trace Minerals

Answer 3

Food content depends on soil, water composition, and processing.

Question 4

Bioavailability

The Trace Minerals

Answer 4

Varies with diet and body functioning.

the proportion of a drug or other substance which enters the circulation when introduced into the body and so is able to have an active effect.

Question 5

Deficiencies

The Trace Minerals

Answer 5

Hard to detect, especially mild cases.
Can cause growth failure in children and other issues.

Question 6

Toxicities

The Trace Minerals

Answer 6

UL only 2.5-11% above RDA; excessive supplement use risks toxicity.
Prefer food sources over supplements.

Question 7

Interactions

The Trace Minerals

Answer 7

Excess of one mineral can cause deficiency or toxicity of another.
Some minerals interfere with each other’s absorption.

Question 8

Roles

Iron

Answer 8

Functions in oxidation-reduction reactions, ATP production, oxygen transport (hemoglobin/myoglobin), and more.

Question 9

Absorption

Iron

Answer 9

Increases when iron stores are low or needs are high (e.g., pregnancy).
Affected by health conditions (e.g., GI diseases).

Question 10

Dietary Forms

Iron

Answer 10

Heme Iron: Animal sources, high bioavailability (~25% absorption).
Nonheme Iron: Plant and animal sources, lower bioavailability (~17% absorption); enhanced by vitamin C, MFP factor.
Inhibited by phytates, calcium, polyphenols.

Question 11

Transport & Storage

Iron

Answer 11

Transported by transferrin, stored in ferritin and hemosiderin.
Regulation by hormone hepcidin (produced in the liver).

Question 12

Deficiency

Iron

Answer 12

Common in toddlers, adolescents, women, and during pregnancy.
Stages: 1) Depleted stores → 2) Reduced transport → 3) Low hemoglobin.
Symptoms: Fatigue, weakness, pale skin, impaired performance.

Question 13

Toxicity

Iron

Answer 13

Causes include hemochromatosis, hemosiderosis, and excess supplements.
Symptoms: Liver damage, infections, fatigue, and organ failure.

Question 14

Recommendations

Iron

Answer 14

RDA: Men 8 mg/day, women 18 mg/day; vegetarians need 1.8x more.
UL: 45 mg/day. Excess supplements can cause GI distress.
Sources: Meat, fish, fortified grains, dark greens, iron cookware.

Question 15

Roles

Zinc

Answer 15

Enzyme cofactor, immune support, growth, insulin function, wound healing, and reproduction.

Question 16

Absorption

Zinc

Answer 16

15-40%; reduced by high intake and phytates.
Enteropancreatic circulation recycles zinc; some lost via feces, urine, and skin.

Question 17

Deficiency

Zinc

Answer 17

Common in developing countries; linked to diets low in meat and high in phytates.
Symptoms: Stunted growth, immune dysfunction, and delayed development.

Question 18

Toxicity

Zinc

Answer 18

UL: 40 mg/day; causes vomiting, diarrhea, and interference with copper metabolism.

Question 19

Sources

Zinc

Answer 19

Protein-rich foods (shellfish, meats, dairy); soil-dependent for plants.

Question 20

Roles

Iodine

Answer 20

Essential for thyroid hormones that regulate metabolism, growth, and nerve/muscle function.

Question 21

Deficiency

Iodine

Answer 21

Leads to goiter, cretinism in pregnancy, and metabolic issues.

Question 22

Toxicity

Iodine

Answer 22

Can enlarge thyroid; UL: 1100 mcg/day.

Question 23

Sources

Iodine

Answer 23

Iodized salt, seafood, dairy, and soil-rich plants.

Question 24

Roles

Selenium

Answer 24

Antioxidant (e.g., glutathione peroxidase) and thyroid hormone regulation.

Question 25

Deficiency

Selenium

Answer 25

Keshan disease (enlarged heart due to selenium-poor soil).

Question 26

Toxicity

Selenium

Answer 26

UL: 400 mcg/day; causes hair/nail loss and nervous system damage.

Question 27

Sources

Selenium

Answer 27

Meat, seafood, whole grains, fruits, and vegetables (soil-dependent).

Question 28

Roles

Copper

Answer 28

Enzyme cofactor in oxygen-related reactions; helps iron metabolism.

Question 29

Deficiency/Toxicity

Copper

Answer 29

Rare but leads to anemia, bone abnormalities, or liver damage if imbalanced.

Question 30

Sources

Copper

Answer 30

Shellfish, nuts, seeds, whole grains, and legumes.