Chapter 13 Flashcards
Definition
The Trace Minerals
Microminerals needed in amounts <100 mg/day.
Functions
The Trace Minerals
Active in digestion, circulation, movement, and nervous system.
Sources
The Trace Minerals
Food content depends on soil, water composition, and processing.
Bioavailability
The Trace Minerals
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.
Deficiencies
The Trace Minerals
Hard to detect, especially mild cases.
Can cause growth failure in children and other issues.
Toxicities
The Trace Minerals
UL only 2.5-11% above RDA; excessive supplement use risks toxicity.
Prefer food sources over supplements.
Interactions
The Trace Minerals
Excess of one mineral can cause deficiency or toxicity of another.
Some minerals interfere with each other’s absorption.
Roles
Iron
Functions in oxidation-reduction reactions, ATP production, oxygen transport (hemoglobin/myoglobin), and more.
Absorption
Iron
Increases when iron stores are low or needs are high (e.g., pregnancy).
Affected by health conditions (e.g., GI diseases).
Dietary Forms
Iron
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.
Transport & Storage
Iron
Transported by transferrin, stored in ferritin and hemosiderin.
Regulation by hormone hepcidin (produced in the liver).
Deficiency
Iron
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.
Toxicity
Iron
Causes include hemochromatosis, hemosiderosis, and excess supplements.
Symptoms: Liver damage, infections, fatigue, and organ failure.
Recommendations
Iron
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.
Roles
Zinc
Enzyme cofactor, immune support, growth, insulin function, wound healing, and reproduction.
Absorption
Zinc
15-40%; reduced by high intake and phytates.
Enteropancreatic circulation recycles zinc; some lost via feces, urine, and skin.
Deficiency
Zinc
Common in developing countries; linked to diets low in meat and high in phytates.
Symptoms: Stunted growth, immune dysfunction, and delayed development.
Toxicity
Zinc
UL: 40 mg/day; causes vomiting, diarrhea, and interference with copper metabolism.
Sources
Zinc
Protein-rich foods (shellfish, meats, dairy); soil-dependent for plants.
Roles
Iodine
Essential for thyroid hormones that regulate metabolism, growth, and nerve/muscle function.
Deficiency
Iodine
Leads to goiter, cretinism in pregnancy, and metabolic issues.
Toxicity
Iodine
Can enlarge thyroid; UL: 1100 mcg/day.
Sources
Iodine
Iodized salt, seafood, dairy, and soil-rich plants.
Roles
Selenium
Antioxidant (e.g., glutathione peroxidase) and thyroid hormone regulation.
Deficiency
Selenium
Keshan disease (enlarged heart due to selenium-poor soil).
Toxicity
Selenium
UL: 400 mcg/day; causes hair/nail loss and nervous system damage.
Sources
Selenium
Meat, seafood, whole grains, fruits, and vegetables (soil-dependent).
Roles
Copper
Enzyme cofactor in oxygen-related reactions; helps iron metabolism.
Deficiency/Toxicity
Copper
Rare but leads to anemia, bone abnormalities, or liver damage if imbalanced.
Sources
Copper
Shellfish, nuts, seeds, whole grains, and legumes.
