Nutrition Test 6

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Nutrition Test 6
2010-05-06 14:19:39
Nutrition Test

Chapters 11 & 12
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  1. Bone Health:
    structure described
    • n Bone
    • structure

    • q Provides
    • strength to support the body

    • q Allows
    • for flexibility

    • q Contains
    • about 65% minerals providing the hardness of bone

    • q Contains
    • 35% organic structures for strength, durability, flexibility

    • q Collagen:
    • fibrous protein in bone tissue
  2. Bone Health:
    bone composition
    • n Two
    • types of bone tissue:

    • q Cortical
    • bone (compact bone)

    • § Very
    • dense tissue

    • § Outer
    • surface of bone

    • § 80%
    • of the skeleton.

    • q Trabecular
    • bone (spongy bone)

    • § “Scaffolding”
    • on the inside of bones

    • § Supports
    • cortical bone

    • § 20%
    • of the skeleton.
  3. Bone Health

    Bone Health: Development

    Bone Health: Process of Development
    • n Bones
    • develop through three processes:

    • q Bone
    • growth - increase in bone size

    • § Completed
    • by age 14 in girls and age 17 in boys

    • q Bone
    • modeling - shaping of bone

    • § Completed
    • by early adulthood

    • § Exercise
    • and overweight increase bone thickness

    • q Bone
    • remodeling - recycling of bone tissue
  4. Bone Health: (remodeling continued)
    • n Bone
    • remodeling involves:

    • q Resorption
    • – surface of bones is broken down by osteoclasts, cells that erode the
    • surface of bones

    • q Formation
    • of new bone matrix by osteoblasts, cells that produce the
    • collagen-containing component of bone that is then mineralized
  5. Bone Health

    Bone Health: Bone Density
    • n Bone
    • density (when bones strongest d/t density)

    • q Peak
    • bone density is reached before the age
    • of 30

    • q Remodeling
    • maintains bone density during early adulthood

    • q Density
    • begins to decrease after age 40 because resorption exceeds new bone formation
  6. Bone Health: How Density Measured
    n Dual energy X-ray absorptiometry (DEXA)

    q Measures density with very low level x-ray

    q Scans full body, or hips & spine

    n Quantitative ultrasound

    • q Uses sound waves to measure bone in heel, shin, and
    • kneecap

    n Peripheral DEXA (pDXA)

    q Measures periphery – wrist, heel or fingers

    n Single energy x-ray absorptiometry

    q Measures wrist or heel
  7. Calcium:
    Overview (Ca)
    • n Calcium
    • is the most abundant major mineral in the body

    • n Bioavailability
    • – the body’s ability to absorb & utilize calcium depends on:

    • q Age
    • & need for calcium

    • q Amount
    • of dietary calcium & vitamin D

    • q Binding
    • factors (phytates, oxalates) in food

    Calcium absorption

    • q Requires
    • vitamin D

    • q Is
    • enhanced in an acid environment
  8. Calcium:
    Functions (Ca)
    • n Functions of
    • calcium

    q Form and maintain bones and teeth

    q Assists with acid-base balance

    q Transmission of nerve impulses

    q Assist in muscle contraction

    • q Maintain blood pressure, initiate blood clotting, and
    • regulating various hormones and enzymes
  9. Regulation of Blood Calcium

    Calcium: Food Sources
    • n Excellent
    • sources include milk products

    • q skim
    • milk, low-fat cheese, nonfat yogurt

    • n Other
    • good sources include

    • q Fortified
    • foods (cottage cheese, orange juice)

    • q Green
    • leafy vegetables (kale, collard greens, broccoli, and cabbage are low in
    • oxalates)

    • q Fish
    • with edible bones (sardines, salmon)
  10. Calcium:
    n Excess excreted form body

    n Supplements can lead to mineral imbalances

    • n Hypercalcemia (high blood calcium) can be caused by
    • cancer or PTH overproduction; may lead to calcium deposits in soft tissues

    n Osteopenia

    n Osteoporosis

    • n Hypocalcemia (low blood calcium) can be caused by
    • kidney disease, vitamin D deficiency, or low PTH production
  11. Vitamin D
    • n Vitamin
    • D

    • q Fat-soluble
    • vitamin & a hormone

    • q Excess
    • is stored in liver and adipose tissue

    • q Can
    • be made by the body when skin is exposed to UV light

    • q Considered
    • a hormone since it is made in one location and acts in another location; made
    • active in the liver & kidneys

    • Vitamin D:
    • Functions

    • n Functions
    • of vitamin D

    • q Required
    • for calcium and phosphorus absorption from the small intestine

    • q Regulates
    • blood calcium levels

    • q
    • Works with PTH to stimulate osteoclasts

    • q Necessary
    • for bone calcification
  12. Vitamin D :
    • n Food:
    • Few food naturally contain high levels of vitamin D

    • q Fatty
    • Fish (salmon, tuna, herring, shark

    • q Fortified
    • milk (most reliable source)

    • q Some
    • fortified cereals & soy products

    • n Sunlight:
    • If optimum conditions

    • q Exposure
    • of unprotected hands, face & arms 20-30 min. two – three times/ week

    • Vitamin D:
    • Toxicity/Deficiency

    n Results from supplements (5-10 X AI)

    • n Hypercalcemia (hi blood Ca) S/S: weakness, loss of
    • appetite, mental confusion; calcium deposits in soft tissues; increased bone
    • loss

    n ↓ bone mass & demineralization of bone

    n Rickets – Vit D deficiency disease in children

    n Osteomalacia – Vit D deficiency disease in adults

    n Osteoporosis – can result from Vit D deficiency

    n Causes: diseases that cause malabsorption of fat
  13. Vitamin K:
    Overview & Functions
    • n Vitamin
    • K

    • q Fat-soluble
    • vitamin stored in the liver

    • q Part
    • of family compounds known as quinones; comes from plants & produced by
    • healthy bacteria in the large intestine

    • n Functions
    • of vitamin K: serves as coenzyme in production of specific proteins

    • q Blood
    • coagulation

    • q Bone
    • turnover

    • Vitamin K:
    • Sources

    • n Good
    • Food Sources: green leafy veggies, veggie oils such as soybean &
    • canola

    • n Healthy
    • bacteria in large intestine produce small amounts of vitamin K

    • Vitamin K:
    • Toxicity/Deficiency

    n No know side effects of consuming excessive Vit K

    n Reduced blood clotting, excessive bleeding

    • n May be caused by: long term antibiotic use; fat
    • malabsorption diseases

    • n Newborns – given vit K at birth d/t lack of bacteria
    • in GI tract
  14. Phosphorus:
    Functions (P)
    • n Phosphorus
    • (as phosphate) is the major intracellular negatively charged electrolyte

    • n Functions
    • of phosphorus

    • q Part
    • of mineral complex of bone

    • q Required
    • for proper fluid balance

    • q Component
    • of ATP, DNA, cell membranes & lipoproteins

    • Phosphorus:
    • Sources

    • n Widespread
    • in many foods

    • q High
    • in protein-containing foods such as milk, meats, eggs

    • q In
    • processed foods as a food additive

    • q In
    • soft drinks as phosphoric acid

    • Phosphorus:
    • Toxicity/Deficiency

    • Excessive Vit D supplements or
    • phosphorus-containing antacids can cause high phosphorus levels, muscle spasms
    • and convulsions

    • The effect on bone loss is not conclusive –
    • additional research needed

    n Rare
  15. Magnesium:
    Functions (Mg)
    • n About 50 – 60% of the body’s magnesium is found in the
    • bones

    n Major mineral

    • n
    • Functions of magnesium

    q A mineral found in bone structure

    q Cofactor for over 300 enzyme systems

    q Required for ATP, DNA, and proteins

    • q Supports vitamin D metabolism, muscle contraction, and
    • blood clotting

    • Magnesium:
    • Sources

    Seafood & green leafy veggies

    Whole grains, seeds & nuts

    • High fiber & plant phytates
    • inhibit absorption

    • High protein rich diets enhance
    • absorption

    Magnesium: Toxicity/Deficiency

    n No toxicity from magnesium in food

    • q Excess magnesium supplements can cause diarrhea,
    • nausea, cramps, dehydration

    n Poor intake can contribute to:

    q Low blood calcium

    q Muscle cramps & seizures

    q Long term associated with osteoporosis
  16. Fluoride: Overview & Functions (F)
    • n Fluoride
    • is a trace mineral.

    • q Ionic
    • form of fluorine

    • q About
    • 99% of the body’s fluoride is stored in teeth and bones

    • n Functions
    • of fluoride

    • q Development
    • and maintenance of teeth and bones

    • q Combines
    • with calcium and phosphorus to protect teeth from bacteria

    Fluoride: Sources

    Sources of fluoride

    • q Fluoridated
    • dental products

    • q Fluoridated
    • water

    • Fluoride:
    • Toxicity/Deficiency

    • q Fluorosis (excess
    • fluoride) creates porous tooth enamel; teeth become stained and pitted

    Deficiency results in dental caries
  17. Osteoporosis:
    • n Decreased
    • bone mass where no obvious disease can be found -

    • n Osteoporosis
    • is a disease characterized by

    • q Low
    • bone mass

    • q Deterioration
    • of bone tissue

    • q Fragile
    • bones leading to bone fractures

    • q Compaction
    • of bone; decreased height

    • q Shortening
    • and hunching of the spine

    Osteoporosis: Risk Factors

    • n Factors
    • influencing the risk of osteoporosis include:

    q Age

    q Gender

    q Genetics

    q Nutrition

    • q Physical
    • activity

    Osteoporosis: Risk Factors

    • n Age is a
    • risk factor for osteoporosis

    q Bone mass decreases with age

    q Age-related hormonal changes influence bone density

    q Older adults are less able to absorb vitamin D

    • n Gender
    • is a risk factor for osteoporosis.

    q 80% of Americans with osteoporosis are women

    q Women have lower bond density than men

    • q Low estrogen production increases bone loss:
    • post-menopausal women and adolescent girls engaged in extreme dieting

    Osteoporosis: Risk Factors

    n Smoking and poor nutrition increase osteoporosis risk

    • q Cigarette smoking effects hormones that influence bone
    • formation & resorption

    q Alcoholism is associated with fractures

    q Caffeine may increase urinary calcium loss

    n Physical activity

    • q Regular exercise stresses bone tissues, stimulates
    • increases in bone density

    • q Weight-bearing activities (walking, jogging) are
    • especially helpful in increasing bone mass

    • q Improved muscle strength & physical stability
    • reduces the risk of falling & bone fractures


    • n Female
    • athlete triad is a condition characterized by:

    • q Eating
    • disorder

    q Amenorrhea

    q Osteoporosis


    • n There
    • is no cure for osteoporosis.

    • n The
    • progression of osteoporosis may be slowed by

    • q Adequate
    • calcium and vitamin D intake

    • q Regular
    • exercise

    • q Anti-resorptive
    • medications
  18. Blood:
    description & function

    n Blood
    is the only fluid tissue in the body
    n Functions

    • q Transport
    • of oxygen and nutrients to cells

    • q Removal
    • of waste products from tissues

    • Blood:
    • composition

    • n Components
    • of blood

    • q Erythrocytes
    • – red blood cells for transporting oxygen through the body

    • q Leukocytes
    • – white blood cells of the immune system

    • q Platelets
    • – cell fragments that assist in blood clotting

    • q Plasma
    • – the fluid portion of the blood for maintaining adequate blood volume

  19. Iron (Fe)
    Overview – Function
    • n Iron
    • is a trace mineral – needed in very small amounts however: Iron deficiency
    • anemia is most common nutrient deficiency in world

    • n Functions
    • of iron

    • q A
    • component of the protein hemoglobin which carries oxygen in erythrocytes

    • q A
    • component of myoglobin which carries oxygen in muscle cells

    • q A
    • coenzyme involved in energy metabolism of carbohydrates, fats, and proteins


    • n Two
    • types of iron are found in foods

    • q Heme
    • iron – found in animal based foods and more absorbable (meat, poultry,
    • fish, clams, oysters)

    • q Non-heme
    • iron – not easily absorbed (fortified cereals & breads and animal
    • products)


    • n Factors
    • that promote iron absorption

    • q Meat
    • factor

    • q Stomach
    • acids

    • q Vitamin
    • C

    • n Factors
    • that impair iron absorption

    • q Phytates,
    • polyphenols, vegetable proteins, fiber, and calcium


    n How Is Iron Transported in the Body?

    • q Transferrin is
    • the primary iron-transport protein in the blood

    • q Receptors on cell surface enable iron transport into
    • the cell

    n What Factors Regulate Total Body Iron?

    q Iron absorbed

    q Iron loss

    q Storage and recycling of body iron

    • Iron:
    • Toxicity/Deficiency

    • n Accidental iron overdose is the most common cause of
    • poisoning deaths in children

    • q Toxicity
    • : S/S nausea, vomiting, diarrhea, dizziness, confusion

    • q Delayed treatment: severe damage to the heart, central
    • nervous system, liver, kidneys

    q Hemochromatosis: excessive absorption of dietary iron and altered iron storage

    n Most common nutrient deficiency in world

    • n Hi risk people: infants, young children, preadolescent
    • girls, premenopausal women, and pregnant women
  20. Zinc:
    (Zn) Functions
    • n Zinc
    • is a trace mineral; <100mg/dy needed

    • q Food
    • sources: red meats, some seafood, whole grains, enriched grains and cereals

    • n Functions
    • of zinc

    • q Coenzyme
    • for hemoglobin production

    • q Maintain
    • protein structures: important in the development and function of immune system

    • q Regulate
    • gene expression

    • Zinc:
    • inhibit/enhance absorption

    • n Dietary factors that inhibit zinc
    • absorption

    q High non-heme iron intake

    q Phytates and fiber (whole grains, beans)

    • n Dietary factors that enhance zinc
    • absorption

    q Animal based protein

    • Zinc:
    • Toxicity/Deficiency

    • q Toxicity
    • can occur from supplements

    q Symptoms: intestinal pain, cramps, nausea, vomiting

    q Depressed immune function

    q Interference with copper and iron absorption.

    q Deficiencies are uncommon in the US

    • q S/S: growth retardation, diarrhea, delayed sexual
    • maturation, infections
  21. Copper:
    Functions (Cu)
    • n Copper
    • is a trace mineral

    • q Food
    • sources: Organ meats, seafood, nuts, seeds, whole grain foods

    • n Functions
    • of copper

    • q Coenzyme
    • for energy metabolism, and for collagen production

    • q Part
    • of superoxide dismutase antioxidant enzyme system

    • q Required
    • for iron transport

    Copper: Absorption

    n Factors that promote copper absorption

    q More copper is absorbed with a low-copper diet

    n Factors that impair copper absorption

    q High zinc intakes

    q High iron intakes

    Copper: Toxicity/Deficiency

    Toxicity is not well studied in humans

    • q S/S: intestinal pain, cramps, nausea, vomiting, liver
    • damage

    q Copper deficiency is rare

    • q S/S: anemia,
    • reduced white blood cells, osteoporosis in children
  22. Vitamin K:
    • n Vitamin
    • K is a fat-soluble vitamin

    • q Sources:
    • Green leafy veggies, such as collard greens, kale, spinach, cabbage

    • n Function
    • of vitamin K

    • q Coenzyme
    • that assists in the synthesis of blood coagulating proteins, prothrombin and
    • procoagulants, factors VII, IX, and X

    • Vitamin K:
    • Absorption

    • n promote
    • vitamin K absorption

    q Gastrointestinal bacteria produce vitamin K

    • q The amount of dietary vitamin K needed depends on
    • intestinal health

    • n Impair
    • vitamin K absorption

    q Impaired dietary fat absorption

    • Vitamin K:
    • Toxicity/Deficiency

    • q No known side effects from consuming large amounts of
    • vitamin K

    q Blood fails to clot, bleeding, hemorrhaging

    q Fat malabsorption reduces vitamin K absorption

    q Newborns lack intestinal bacteria
  23. Folate:
    Overview & Functions
    • n Folate
    • is a water-soluble vitamin

    • n Bioavailability
    • depends on source: better from supplements & fortification – less from food

    • q Sources:
    • breads, flours, pasta, grain products are fortified; liver, spinach, lentils,
    • oatmeal, asparagus

    • n Functions
    • of folate

    • q DNA
    • synthesis, amino acid metabolism

    • q Critical
    • for cell division of very early embryos

    • q Functions
    • with B12 and B6 metabolism

    • Folate:
    • Toxicity/Deficiency

    • q Toxicity
    • can occur with supplements

    q Toxicity can mask vitamin B12 deficiency

    • q Symptoms are intestinal pain, cramps, nausea,
    • vomiting, liver damage

    q Severe deficiency :Macrocytic anemia

    q Elevated homocysteine

    • q Neural tube defect in developing embryo of pregnant
    • woman
  24. Vitamin B12: Overview/Functions
    • n Vitamin
    • B12 is a water soluble vitamin

    • q Requires
    • acidic environment (stomach) and protein intrinsic factor (IF) for absorption

    • q Stored
    • in the liver

    • n Functions
    • of vitamin B12

    • q Coenzyme
    • for DNA synthesis

    • q Maintains
    • myelin sheath of nerve fibers

    • q Metabolism
    • of amino acid homocysteine

    Vitamin B12 : Sources

    • n Sources
    • of vitamin B12

    • q Available
    • exclusively from animal sources

    • q Vegan
    • diet may obtain vitamin B12 from fortified foods, supplements, or
    • injections

    Vitamin B12 : Toxicity/Deficiency

    q No known adverse effects of excess

    • q Deficiency
    • is rare

    q Gastrointestinal & neurologic effects

    q Pernicious anemia
  25. Neural Tube Defects
    • n A woman’s need for folate
    • dramatically increases during pregnancy.

    • q Critical, very early in
    • pregnancy

    • n Folate is required for cell
    • division and proper formation of the neural tube.

    • n The neural tube develops
    • into the brain and spinal cord.

    • n All women capable of
    • becoming pregnant should consume an additional 400 micrograms of folate daily
  26. Vascular Disease
    • n Folate and vitamin B12
    • are required for the breakdown of the amino acid homocysteine

    • n Low folate and vitamin B12
    • intake may increase the level of homocysteine

    • n High homocysteine levels are
    • associated with greater cardiovascular and cerebrovascular disease risk
  27. Anemia means “without blood”, any condition of low
    hemoglobin levels
    • n
    • Iron-deficient
    • Anemia

    • q Results in small red blood cells that do not contain
    • enough hemoglobin

    • q S/S: fatigue, pale skin, impaired work performance,
    • depressed immune function, impaired memory

    • n
    • Pernicious
    • Anemia

    q Occurring after the loss of specific cells of stomach

    • q Primary cause of vita B12 deficiency is the
    • lack of intrinsic factor (IF)

    q Occurs d/t low B12 in diet

    q S/S: pale skin, reduced energy, fatigue

    • Anemia:
    • continued

    • n
    • Macrocytic
    • (megaloblastic) Anemia

    q caused by severe folate deficiency

    • q Results in enlarged red blood cells containing
    • insufficient hemoglobin

    • q S/S: common symptoms of anemia including: weakness,
    • fatigue, difficulty concentrating, irritability, headache, shortness of breath
  28. Immune System
    • n What
    • Is the Immune System?

    • q A
    • healthy immune system protects the body from infectious diseases, helps heal
    • wounds, and guards against the development of cancers

    • n How
    • Does It Function?

    • q Nonspecific
    • immune function

    • q Specific
    • immune function

    Immune System

    • n How
    • does nutrition affect the immune system?

    • q A
    • nourishing diet provides all the nutrients the immune system needs

    • q Single-nutrient
    • subclinical deficiencies can cause subtle abnormalities in immunity

    • q Protein/energy
    • malnutrition and severe deficiencies of several micronutrients result in
    • functional immunodeficiency
  29. Immune
    System: Functions of Protein/Omega Fatty
    n Protein/energy malnutrition impairs immune function

    q Malnutrition increases the risk for infection

    • q Infection depresses appetite and often causes vomiting
    • and diarrhea

    • q Decreased appetite, vomiting, and/or diarrhea cause
    • malnutrition which increases vulnerability to infection

    • q Anergy is
    • the diminished ability of the immune system to respond to antigens

    • n Essential fatty acids are precursors for signaling
    • molecules eicosanoids

    q Omega 6 FA’s produce inflammatory mediators

    q Omega 3 FA’s help relieve inflammation
  30. Immune
    System: Vitamin/Mineral Contributions
    • q Vitamin A
    • protects the barrier function of the mucosa

    • q
    • Vitamin C and vitamin E protect phagocytes from reactive
    • oxygen species

    • q Zinc assists
    • immune cell gene expression & protein synthesis

    • q Copper
    • deficiency reduces lymphocyte proliferation

    • q Iron deficiency
    • & iron overload both impair immune function

    • q Selenium
    • deficiency & toxicity impair immune function
  31. Immune
    System: Probiotics & Prebiotics
    • n Probiotics,
    • food or supplements that contain live bacteria, are thought to protect against
    • pathogens by:

    • q Colonizing
    • the gut

    • q Inhibiting
    • growth of pathogens

    • q Stimulating
    • immune response

    • n Prebiotics
    • are nondigestible fibers in foods that are fermented by beneficial bacteria and
    • promote their multiplication (food for healthy bacteria)