Chapter 7 Power Point

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Chapter 7 Lecture

Chapter 7:Minerals: Building and Moving Our Body

Learning Outcomes

1. Distinguish between major, trace, and ultra-trace minerals.

2. Explain why certain minerals are referred to as electrolytes and identify their primary functions in the body.

3. Explain how the level of sodium in your blood can affect your blood pressure.

4. Identify two trace minerals important in energy metabolism.

Learning Outcomes

5. Identify two trace minerals essential for the body's synthesis of thyroid hormones.

6. Explain how the body uses iron, and identify dietary sources and factors affecting its absorption.

7. Discuss the role of zinc in metabolism and immune function, and identify common food sources.

Learning Outcomes

8. Identify the four mineral components of bone and explain how bone is formed and maintained.

9. State the four primary functions of calcium.

10.Discuss the risk factors and available treatments for osteoporosis.

What Are Minerals?

• Minerals• Solid, elemental substances• Do not contain carbon• Are not broken down by natural processes

like digestion• Able to carry an electrical charge

Functions of the Major and Trace Minerals

Major Minerals

• Major minerals• Required in larger amounts• At least 100 mg/day are needed

Calcium Magnesium

Sodium Sulfur

Potassium Chloride

Phosphorus

Major Minerals

Trace Minerals

• Trace minerals• Required in smaller amounts• Less than 100 mg/day are needed

Selenium Manganese

Fluoride Iron

Iodine Zinc

Chromium Copper

Trace Minerals

Ultra-Trace Minerals

• Ultra-trace minerals• Less than 1 mg/kg body weight needed per

Boron Molybdenum

Nickel Silicon• Only molybdenum is considered essential; it

has an RDA of 45 µg/day.

Electrolytes

• Body fluid is the primary building block of cellular structure and contains:• water• electrolytes: mineral salts dissolved in water,

including:• sodium• potassium• chloride• phosphorus

Electrolytes

• Electrolytes have many different functions in the body.• Form ions: electrically charged particles• Carry electrical charges• Maintain fluid balance because they:

• strongly attract water• do not move easily across cell membranes

Fluid Balance

Sodium is Part of Table Salt

• Functions of sodium• Fluid and electrolyte balance• Associated with blood pressure and pH

balance in the body• Required for nerve impulse transmission• Assists in the transport of certain nutrients

(e.g., glucose) into body cells

• Recommended intake• AI is 1,500 mg/day (a little more than 1/2 a

teaspoon)• Sources of sodium

• Processed foods typically contain added sodium.

• Hypertension • Blood pressure above the average range• Not necessarily caused by sodium, but

hypertension is more common in people who consume more sodium.

• DASH diet ("Dietary Approaches to Stop Hypertension") can significantly reduce blood pressure.

The DASH Eating Plan

Potassium Helps Maintain Healthful Blood Pressure• Functions of potassium

• Balance of fluids and sodium• Very important in muscle contractions and

transmission of nerve impulses• High potassium intake helps maintain a lower

blood pressure.

Potassium Helps Maintain Healthful Blood Pressure• Recommended intake

• AI for adults is 4.7 g/day• Sources of potassium

• Processed foods are usually low in potassium.

• Fresh fruit, vegetables, and whole grains are good sources of potassium.

Potassium Helps Maintain Healthful Blood Pressure

Potassium Helps Maintain Healthful Blood Pressure• Potassium toxicity is rare in healthy people

because the kidneys excrete the excess.• Potassium deficiency is also rare but can occur

in patients with kidney disease, loss of body fluids and abuse of alcohol or laxatives.

Chloride

• Functions of chloride• Works with phosphorus to maintain correct

fluid balance• Assists the immune system in killing bacteria• Assists in the transmission of nerve impulses

Chloride

• Sources of chloride:• Salt present in foods• Some fruits and vegetables• There are no known toxicity symptoms, and

chloride deficiencies are also rare.

Chromium

• Chromium is:• a trace mineral• important in carbohydrate metabolism• found especially in mushrooms, prunes, dark

chocolate, nuts, whole grains, and cereals• not toxic; deficiency is uncommon in the

United States

Manganese

• Manganese is:• a trace mineral• involved in energy metabolism• involved in the production of bone and

cartilage• deficiency is uncommon in humans

Sulfur

• Sulfur is:• a major mineral• a component of the B vitamins thiamin and

biotin• essential to the shape of proteins• not known to be toxic, deficiency is

uncommon

Iodine

• Iodine is:• a trace mineral• critical for making thyroid hormones• found in saltwater fish• added to table salt (iodized salt)

• Both iodine deficiency and toxicity can result in hypothyroidism and goiter.

• Iodine deficiency in pregnancy increases risk of birth defects.

Selenium

• Selenium is:• a trace mineral• found in a few amino acids• necessary for making thyroid hormones• an antioxidant to protect vitamin E reserves

and safeguard cell membranes• found especially in organ meats and nuts

Selenium

• Blood is the only fluid tissue in the body.• Functions

• Transport of oxygen and nutrients to cells• Removal of wastes from tissues

• Components of blood• Erythrocytes: red blood cells for transporting

oxygen through the body• Leukocytes: white blood cells of the immune

system• Platelets: cell fragments that assist in blood

clotting• Plasma: the fluid portion of the blood

• Iron is: • a trace mineral• a component of the protein hemoglobin that

carries oxygen in erythrocytes• a component of myoglobin that carries

oxygen in muscle cells• a coenzyme involved in energy metabolism of

carbohydrates, fats, and proteins

Iron Absorption

• Two types of iron are found in foods.• Heme iron: found in animal-based foods and

more absorbable• Non-heme iron: not easily absorbed

Iron Absorption

• Iron absorption is increased by:• eating meat, poultry, or fish• taking a Vitamin C supplement with food

• Iron absorption is decreased by:• phytates (chemicals in legumes, rice, and

whole grains)• black tea, coffee, and red wine• soybean-based protein and calcium

• Recommended intake• RDA varies based on age, gender, and other

factors.• 1.8 times higher for vegetarians• Higher for young women than for men

• Sources of iron• Meat, poultry, fish, clams, oysters, enriched

cereals and breads• Cooking in cast iron increases iron content.

Sources of Iron

• What if we consume too much iron?• Iron overdose is the most common cause of

poisoning deaths in children.• Toxicity symptoms: nausea, vomiting,

diarrhea, dizziness, confusion• Delayed treatment of iron toxicity can result in

severe damage to the heart, central nervous system, liver, kidneys.

• What if we don't consume enough iron?• Iron deficiency is the most common nutrient

deficiency in the world.• Iron-deficiency anemia: red blood cells do

not contain enough hemoglobin• High-risk groups include infants, young

children, preadolescent girls, menstruating women, and pregnant women.

• Zinc is:• a trace mineral• a coenzyme for hemoglobin production and

for many other enzymes• required for proper development and function

of the immune system• required for normal growth

• Recommended intake• The need for zinc is small, but the amount of

absorption is variable.• Vegetarians may need zinc supplements.

• Sources of zinc• Red meats, some seafood, whole grains,

enriched grains and cereals

• What if we consume too much zinc?• Toxicity can occur from supplements.• Symptoms are intestinal pain, cramps,

nausea, vomiting, loss of appetite.• What if we don't consume enough zinc?

• Deficiencies are uncommon in the United States.

• Symptoms are growth retardation, diarrhea, delayed sexual maturation.

Copper

• Copper:• is a trace mineral• contributes to blood tissue, collagen, and

tissues surrounding nerves• is required for iron transport• is involved in production of chemical

neurotransmitters required for brain function

Copper

• Recommended intake• RDA for adults is 900 mg/day

• Sources of copper• Organ meats, seafood, nuts, seeds, whole

grain foods

Copper

• What if we consume too much copper? • Toxicity is not well studied in humans.

• What if we don't consume enough copper?• Copper deficiency is rare, but high intake of

zinc and/or iron can reduce copper absorption.

Bone Health

• Bone structure• Provides strength to support the body• Allows for flexibility• Composed of roughly 65% minerals for

density and hardness• Collagen fibers: fibrous protein in bone

tissue providing strength, durability, and flexibility

Bone Health

• Two types of bone tissue• Cortical bone (compact bone): very dense

tissue making up 80% of the skeleton• Trabecular bone (spongy bone):

"scaffolding" on the inside of bones; supports cortical bone and makes up 20% of the skeleton

Bone Health

• Bone density• Refers to the strength of bones• Peak bone density is reached before the age

of 30.• Density begins to decrease after age 40

because breakdown exceeds new bone formation.

Bone Health

• Bone mass is regularly recycled by a process of remodeling.• Breakdown: surface of bones is broken down

by osteoclasts• Osteoclasts are cells that erode the surface of

bones.

• Formation of new bone by osteoblasts• Osteoblasts produce the collagen-containing

component of bone.

Bone Health

Calcium

• Calcium: • is the most abundant major mineral in the

body• is required to form and maintain bones and

teeth• assists with acid–base balance• is critical for transmission of nerve impulses• assists in muscle contraction

Calcium

• Recommended intake• AI values vary with age and gender. • Intake is limited by bioavailability–the

amount that can be absorbed.• Sources of calcium

• Skim milk, low-fat cheese, nonfat yogurt, green leafy vegetables

Calcium Metabolism

Click on the Calcium Metabolism link separate

from the power point.

Common Sources of Calcium

Calcium

• What if we consume too much calcium?• Excess calcium is excreted from the body.• Calcium supplements can lead to mineral

imbalances.• Severe hypercalcemia can lead to death.

• What if we don't consume enough calcium?• Long-term consequence of inadequate

calcium is osteoporosis.

Phosphorus

• Phosphorus is:• a major mineral• critical for proper bone formation• found in ATP, DNA, RNA• required to regulate biochemical pathways by

activating or deactivating enzymes• a major component of the cell membrane

Phosphorus

• Recommended intake• RDA for phosphorus is 700 mg/day

• Sources of phosphorus• Widespread in many foods• Found in high amounts in foods that contain

protein (e.g., meat, milk, eggs)

Phosphorus

• What if we consume too much phosphorus?• Causes muscle spasms, convulsions

• What if we don't consume enough phosphorus?• Deficiencies of phosphorus are rare.• Can occur with alcohol abuse or in elderly

people with poor diets

Magnesium

• Magnesium: • is a major mineral• assists over 300 enzyme systems to function

properly• is required for the production of ATP, DNA,

and proteins• supports muscle contraction and blood

clotting

Magnesium

• Recommended intake• RDA varies based on age and gender.

• 310 mg/day for women age 19–30• 400 mg/day for men age 19–30

• Sources of magnesium• Green leafy vegetables, whole grains, seeds,

nuts, seafood, beans

Magnesium

• What if we consume too much magnesium?• No toxicity from magnesium in food• Magnesium supplements can cause diarrhea,

nausea, cramps, dehydration.• What if we don't consume enough

magnesium?• Low magnesium can result in low blood

calcium and osteoporosis.

Fluoride

• 99% of the body's fluoride is stored in teeth and bones.

• Fluoride:• is a trace mineral• is required for proper development and

maintenance of teeth and bones• combines with calcium and phosphorus to

protect teeth from bacteria

Fluoride

• Recommended intake• RDA varies by gender and increases with age

during childhood.• Sources of fluoride

• Fluoridated dental products• Fluoridated water• Tea

Fluoride

• What if we consume too much fluoride?• Fluorosis (excess fluoride) creates porous

tooth enamel; teeth become stained and pitted.

• What if we don't consume enough fluoride?• Dental caries (cavities)

Osteoporosis

• Osteoporosis is a disease characterized by:• low bone mass• deterioration of bone tissue• fragile bones leading to bone fractures• compaction of bone; decreased height• shortening and hunching of the spine

Osteoporosis

• Factors influencing the risk of osteoporosis include:• age• gender• genetics• smoking• nutrition• physical activity

Osteoporosis

• Age is a factor for osteoporosis because:• bone mass decreases with age• age-related hormonal changes influence

bone density• older adults are less able to metabolize

vitamin D

Osteoporosis

• Gender is a risk factor for osteoporosis.• 80% of Americans with osteoporosis are

women.• Women have lower bone density than men.• Estrogen loss in post-menopausal

women causes increased bone loss.

Osteoporosis

• Nutritional factors may affect the risk for osteoporosis.• Total energy intake• Calcium and vitamin D are important for

proper bone development and maintenance of bone density.

• Diets high in fruits and vegetables are associated with improved bone health.

• Alcohol abuse increases risk.

Osteoporosis

• Physical activity influences the risk for osteoporosis.• Regular exercise causes stress to bones,

leading to increased bone mass.• Weight-bearing activities (walking, jogging,

weight training) are especially helpful in increasing bone mass.

Osteoporosis

• There is no known cure for osteoporosis.• The progression of osteoporosis may be slowed

by:• adequate calcium and vitamin D intake• regular exercise• medications to slow or stop bone breakdown

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