CHAPTER

7Minerals: Building and Moving Our Body

Chapter 7 Outline

I. What Are Minerals?

A. Minerals are solid, crystalline substances that do not contain carbon and are not broken down during digestion.

1. Minerals carry an electrical charge.

2. Minerals are classified according to how much of them our bodies need and how much is present in our bodies.

a. Major minerals are required in amounts greater than 100 mg per day.

b. Trace minerals are required in amounts less than 100 mg per day.

c. Ultra-trace minerals are required in amounts lower than 1 mg/kg of body weight per day.

II. Essential Electrolytes: Sodium, Potassium, Chloride, and Phosphorus

A. Electrolytes maintain fluid balance in our bodies.

1. Electrolyte imbalances can cause dehydration and death.

B. Sodium is part of table salt.

1. Why do we need sodium?

a. Sodium is the major mineral in the fluid outside of the cell.

b. It helps to maintain fluid balance, blood pressure, and acid-base balance.

c. Sodium assists with transmission of nerve signals and aids in muscle contraction and relaxation.

d. Sodium assists in the absorption of nutrients such as glucose.

e. Sodium enhances flavor in food and acts as a preservative.

2. How much sodium should we consume?

a. The AI for sodium is 1,500 mg.

b. Most people in the United States consume between 3,000 and 6,000 mg.

c. Processed foods generally contain higher sodium levels than unprocessed foods.

3. Does sodium play a role in high blood pressure?

a. Consuming excess sodium causes bloating.

b. Excessive sodium consumption can contribute to high blood pressure in some individuals.

C. Potassium helps maintain healthful blood pressure.

1. Potassium helps to maintain fluid balance and assists in maintaining blood pressure.

Copyright © 2016 Pearson Education, Inc. 47

a. The best sources of potassium include fresh fruits and vegetables.

b. Toxicity in healthy people is rare.

c. Dietary deficiency is rare.

d. Individuals who lose excessive amounts of body fluids are at risk of potassium deficiency.

D. Chloride and phosphorus also assist fluid balance.

1. Chloride is involved in fluid balance, transmission of nerve impulses, and is a part of hydrochloric acid (HCl) in the stomach.

2. Chloride deficiency is rare.

3. Chloride deficiency may occur during conditions of severe dehydration and frequent vomiting.

4. Phosphorus is pooled with potassium inside our cells.

a. Phosphorus helps maintain fluid balance and bone health.

III. Mineral Power Plants: Chromium, Manganese, Sulfur, Iodine, and Selenium

A. Chromium and manganese are important in metabolism.

1. Chromium is a trace mineral that plays an important role in carbohydrate metabolism, RNA and DNA metabolism, growth, and immune function.

a. Food sources include mushrooms, prunes, dark chocolate, nuts, whole grains, asparagus, brewer’s yeast, some beers, and red wine.

b. There appears to be no toxicity and deficiency is rare.

2. Manganese is a trace mineral that is involved in energy metabolism and urea synthesis.

a. Manganese is widespread in foods.

b. Manganese toxicity and deficiency are rare.

B. Sulfur is a component of other nutrients.

1. Sulfur is required by the liver to assist in the detoxification of alcohol and drugs.

2. There is no known deficiency or toxicity for sulfur.

C. Iodine and selenium help make thyroid hormones.

1. Iodine is needed for synthesis of thyroid hormones.

2. Good food sources include iodized salt, saltwater fish, and shrimp.

3. An iodine deficiency and toxicity can cause a goiter.

4. Selenium is a trace mineral that works with iodine and is an antioxidant.

5. Selenium is found in nuts and organ meats.

6. Selenium toxicity is rare and deficiency is associated with rare forms of heart disease and arthritis.

IV. The Blood Fortifiers: Iron, Zinc, and Copper

A. Blood transports nutrients, oxygen, and waste products; it is composed of four compo-nents.

1. Erythrocytes (red blood cells) transport oxygen.

2. Leukocytes (white blood cells) are the key to our immune system.

3. Platelets (cell fragments) assist in formation of blood clots.

4. Plasma is the fluid portion of the blood.

B. Iron is a key component of hemoglobin.

48 INSTRUCTOR MANUAL FOR NUTRITION FOR LIFE, 4/e Copyright © 2016 Pearson Education, Inc.

1. Why do we need iron?

2. What factors affect iron absorption?

a. Heme iron is a part of hemoglobin and myoglobin and is the best-absorbed form of iron.

b. Non-heme iron is not absorbed as well as heme iron.

i. A factor in meat, poultry, and fish and vitamin C increase iron absorption of non-heme iron.

ii. Phytates, polyphenols, soy protein, and calcium decrease iron absorption.

3. What are iron needs and sources?

a. Good food sources of heme iron are meat, poultry, and fish.

b. Good food sources of non-heme iron are fortified grains, some vegetables, andlegumes.

4. What happens if we consume too much or too little iron?

a. Acute iron toxicity may cause nausea, vomiting, diarrhea, dizziness, confusion, and rapid heartbeat.

b. Iron-deficiency anemia is the most common nutrient deficiency in the world.

C. Zinc assists the work of many different enzymes.

1. Good food sources include red meat, some seafood, and whole and enriched grains.

2. Zinc toxicity can cause intestinal pain, nausea, vomiting, loss of appetite, diarrhea, and headaches.

a. Excessive intake can also depress the immune system and interfere with copper absorption.

3. Zinc deficiency can cause growth retardation, diarrhea, delayed sexual maturation and impotence, eye and skin lesions, hair loss, impaired appetite, and impaired immunity.

D. Copper helps transport iron and build tissues.

1. Good food sources include organ meats, seafood, nuts, seeds, and whole grains.

2. Toxicity of copper is not well studied and deficiency is rare.

V. The Bone Builders: Calcium, Phosphorus, Magnesium, and Fluoride

A. Bones are made up of minerals and protein.

1. Collagen is a protein that forms strong fibers in bone and connective tissue.

2. There are two types of bone.

a. Cortical bone is dense and comprises 80 percent of our skeleton.

b. Trabecular bone is porous bone tissue that makes up 20 percent of our skeleton.

B. How do bones stay healthy?

1. Bone growth and modeling determine the size and shape of our bones.

2. Bone remodeling maintains a balance between breakdown and repair.

a. Bone density continues to develop into early adulthood.

b. Bone mass is regularly recycled through remodeling.

i. Osteoclasts break down bone.

ii. Osteoblasts build bone.

C. Calcium is a key component of bones.

1. Why do we need calcium?

a. Provides structure to bones and teeth

Copyright © 2016 Pearson Education, Inc. CHAPTER 7  Minerals: Building and Moving Our Body 49

b. Assists with acid-base balance

c. Critical for normal transmission of nerve impulses

d. Assists in muscle contraction

e. Maintains healthy blood pressure

f. Initiates blood clotting

g. Regulates various hormones and enzymes

2. How much calcium is absorbed?

a. Phytates, oxalates, iron, zinc, magnesium, and phosphorus all decrease absorption.

b. Vitamin D increases absorption of calcium.

3. What are calcium needs and sources?

a. Dairy products are the most common sources of calcium.

b. Adults should consume between 1,000 and 1,200 mg per day.

4. What happens if we consume too much or too little calcium?

a. Consuming excess calcium can interfere with absorption of other minerals.

b. There are no short-term symptoms associated with consuming too little calcium because our bodies will remove calcium from bone if necessary.

c. The long-term effect of low calcium intake is osteoporosis.

D. Phosphorus is part of the mineral complex of bone.

1. Phosphorus helps to maintain fluid balance, and is a component of ATP, cell mem-branes, and lipoproteins.

2. Dietary sources of phosphorus are widespread and found in high amounts in protein-containing foods.

a. Phosphorus is found in soft drinks and added to foods as a food additive.

3. Severely high blood phosphorus can cause muscle spasms and convulsions.

4. Phosphorus deficiencies are rare.

E. Magnesium is found in bone and soft tissue.

1. Other functions include muscle contractions, blood clotting, and enzyme assistance.

2. Good food sources are green leafy vegetables, hard water, whole grains, seeds, and nuts.

3. Toxicity symptoms include diarrhea, nausea, and abdominal cramps.

4. Deficiency is uncommon in healthy adults.

a. Symptoms include muscle cramps, seizures, and nausea.

b. May result in osteoporosis.

F. Fluoride supports our teeth and bones.

1. Good sources of fluoride are fluoridated water and dental products.

2. Consuming too much fluoride causes fluorosis of the teeth.

3. The primary result of fluoride deficiency is dental caries.

VI. Are You At Risk For Osteoporosis?

A. Osteoporosis is a disease characterized by low bone mass and deterioration of bone tissue.

1. Risk factors include age, gender, genetics, smoking, nutrition, and physical activity.

2. There is no cure for osteoporosis, but there are treatments that can slow or reverse bone loss.

50 INSTRUCTOR MANUAL FOR NUTRITION FOR LIFE, 4/e Copyright © 2016 Pearson Education, Inc.