Module 10

Minerals

Inorganic nutrients that are essential in the diet.

Macrominerals

Minerals present in greater amounts in the body, with a recommended intake of ≥100 mg per day.

Examples of macrominerals

Calcium, phosphorus, potassium, sulfur, sodium, chloride, and magnesium.

Microminerals

Also called trace minerals, they have a recommended intake of <100 mg per day.

Examples of microminerals

Iron, copper, manganese, and iodine.

Calcium

The most abundant mineral in the body, primarily found in bones and teeth.

Blood calcium regulation

Controlled by Vitamin D and parathyroid hormone.

Hydroxyapatite

The crystal formed by calcium and phosphorus that provides bone strength.

Functions of calcium

Muscle contraction, nerve impulse conduction, and blood clotting.

Pre-eclampsia

A condition in pregnant women characterized by high blood pressure and protein in urine.

Osteoporosis

A common bone disease leading to porous bones and an increased risk of fractures.

Calcium absorption

Average absorption of calcium ingested is about 30%.

RDA for calcium (adults 19–50 yrs.)

1,000 mg per day.

Phosphorus

The second most abundant mineral in the body, primarily in bones and teeth.

Key role of phosphorus

Part of bones and teeth, facilitates enzyme function, and component of ATP.

RDA for phosphorus (adults)

700 mg per day.

Magnesium

The macromineral found in the smallest amount in the body; ~35 g on average.

RDA for magnesium (men)

400 mg per day.

RDA for magnesium (women)

320 mg per day.

Functions of zinc

Involved in immune function, DNA replication, antioxidant enzyme function, and wound healing.

Signs of zinc deficiency

Limited growth, poor sexual development, abnormal hair/nails, and impaired immune function.

Iron's primary role

Assists in the delivery of oxygen to tissues and cells.

Iron deficiency anemia

A clinical condition caused by low iron stores, leading to too low hemoglobin levels.

Heme iron

Iron form found in hemoglobin, primarily from meats and better absorbed.

Non-heme iron

Elemental form of iron found in plant-based foods, less readily absorbed.

RDA for iron (women 19-50 yrs.)

18 mg/day.

RDA for iron (men and women over 50)

8 mg/day.

Copper

A micromineral important for iron metabolism and antioxidant defenses.

Copper absorption

50% of dietary copper is absorbed primarily in the small intestine.

RDA for copper

900 µg per day.

Selenium

An essential mineral that supports the body’s antioxidant defense system.

Role of selenium

Part of the antioxidant enzyme glutathione peroxidase.

RDA for selenium

55 µg per day.

Iodine's primary function

Facilitates the production of thyroid hormone that controls metabolism.

Iodine deficiency effects

Can lead to the enlargement of the thyroid gland (goiter) and developmental delays.

RDA for iodine

150 µg per day.

Calcium's effect on muscle contraction

Calcium enters muscle cells to initiate contraction.

Calcium's role in the nervous system

Regulates the release of neurotransmitters.

Factors decreasing calcium absorption

Phytates and oxalates found in some plant foods.

Calcium sources

Dairy products, canned sardines, broccoli, and green leafy vegetables.

Phosphorus food sources

Meat, fish, poultry, eggs, and dairy products.

Magnesium food sources

Green leafy vegetables, nuts, legumes, and whole grains.

Sulfur's storage site

Primarily in amino acids methionine and cysteine.

Iron toxicity symptoms

Abdominal pain, fatigue, and potential liver damage.

Zinc food sources

Meat, poultry, nuts, and whole grains.

Copper food sources

Organ meats, shellfish, chocolate, and nuts.

Selenium food sources

Seafood, Brazil nuts, meats, eggs, and wheat.

Iodine food sources

Seafood and iodized salt.

Major organ responses to low blood calcium

Intestine, bones, and kidneys.

Calcium's alternate functions

Plays a role in blood clotting and may protect against hypertension.

Osteopenia

Condition of weakened bones, precursor to osteoporosis.

Calcium's role in hormone regulation

Influences cellular calcium levels affecting hormone action.