Chapter 15 ( Bone health and body defense systems)

The 250 mg of calcium found in a cup of spinach ________.
A. is the only source of calcium for a vegan
B. has low bioavailability because the calcium is bound to oxalic acid
C. is poorly absorbed unless the spinach is cooked
D. has low bioavailability because the calcium is bound to phytic acid

B. has low bioavailability because the calcium is bound to oxalic acid

Individuals advised to consume calcium supplements should consume ________.
A. about 2,000 mg in a single dose each day
B. only calcium citrate as other calcium salts are poorly absorbed
C. an amount of no more than 500 mg with or just after a meal D. the calcium supplement at the same time as other mineral supplements

C. an amount of no more than 500 mg with or just after a meal

Absorption of dietary calcium in the duodenum is aided by ________. A. consumption of lactose B. acidic environment
C. 1, 25 (OH)2 vitamin D
D. All of these choices are accurate

D. All of these choices are accurate

Which of the following population groups has the highest rate of calcium absorption?
A. Postmenopausal women
B. Pregnant women
C. Premenopausal women (not pregnant or lactating)
D. Athletes in training

B. Pregnant women

Measuring blood calcium levels is not an accurate indicator of total body calcium because ________.
A. calcium in the blood reflects only the most recent dietary intake of calcium
B. there are no reliable tests for measuring blood calcium
C. blood calcium levels vary according to the intake of other positive ions (e.g., sodium, potassium, and magnesium) D. blood calcium levels are strictly controlled by hormones and do not reflect total body stores

D. blood calcium levels are strictly controlled by hormones and do not reflect total body stores

Which factor(s) limits absorption of dietary calcium?
A. Phytic acid
B. Chronic diarrhea
C. Tannins in tea
D. Vitamin D deficiency
E. All of these choices are accurate

E. All of these choices are accurate

Parathyroid hormone elevates blood calcium levels by ________. A.increasing the synthesis of 1, 25 (OH)2 vitamin D
B. reducing calcium excretion by the kidneys
C. increasing bone resorption by osteoclast activity
D. All of the choices are accurate

D. All of the choices are accurate

Which of the following foods provides the greatest amount of calcium per serving?
A. 1 cup of yogurt
B. 2 oz. cheddar cheese
C. 3 oz. canned salmon with bones
D. 1 cup cooked spinach

A. 1 cup of yogurt

Assuming that milk is the only source of dietary calcium, how much milk must an adolescent drink every day to meet the RDA for calcium?
A. 2 cups
B. 3 cups
C. 4 cups
D. 5 cups

D. 5 cups

The two life stage groups with the highest RDAs for calcium are _________ and _________.
A. children; adolescents
B. infants; children
C. adolescents; adults over age 50
D. infants; adolescents

C. adolescents; adults over age 50

The very dense outer surface of bone is called ________. A. osteoclastic bone B. osteoblastic bone C. trabecular bone
D. cortical bone

D. cortical bone

At the end of long bones, inside the spinal vertebrae, and inside the flat bones of the pelvis, is a spongy type of bone known as ________.
A. osteoclastic bone B. osteoblastic bone C. trabecular bone
D. compact bone

C. trabecular bone

________ replacement after menopause greatly reduces bone loss in women.
A. Calcium
B. Calcitriol
C. Estrogen
D. Calcitonin

C. Estrogen

In addition to its role in bone development and maintenance, calcium is also required for ________.
A. blood clotting, transmitting nerve impulses, and muscle contraction
B. regulating potassium excretion, normal kidney function, and regulating intracellular water content C. phospholipid synthesis, muscle contraction, and formation of DNA and RNA D. blood clotting, magnesium absorption, and insulin release from the pancreas

A. blood clotting, transmitting nerve impulses, and muscle contraction

The bones most likely to be affected by the disease osteoporosis include the ________. A. ankle, shoulder, and neck B. hip, thigh, and ankle
C. hip, wrist, and vertebrae in the spine
D. wrist, forearm, and neck
E. All of these are correct as all bones are affected equally by osteoporosis

C. hip, wrist, and vertebrae in the spine

Risk factors for osteoporosis include ________.
A. overweight and obesity B. amenorrhea
C. African-American race
D. high levels of physical activity

B. amenorrhea

Phosphorus absorption is promoted by the hormone ________.
A. calcitonin
B. 1, 25 (OH)2 vitamin D C. cholecalciferol
D. aldosterone

B. 1, 25 (OH)2 vitamin D

The RDA for adults for phosphorus is ________.
A. the same as calcium
B. twice the amount of calcium C. 700 mg/d
D. 200 mg/d

C. 700 mg/d

Good food sources of phosphorus include ________. A. fruits and vegetables
B. nuts and oils
C. dairy products, meats, and cereals
D. dairy products and leafy green vegetables

C. dairy products, meats, and cereals

The richest dietary sources of magnesium are ________.
A. animal products, e.g., beef and milk
B. plant products, e.g., green vegetables, beans, whole grains C. fats and oils
D. bottled waters

B. plant products, e.g., green vegetables, beans, whole grains

Magnesium deficiency is most often caused by ________. A. excessive intakes of sodium and potassium
B. low dietary intake of magnesium
C. GI disorders that cause prolonged diarrhea or vomiting D. osteopenia or osteoporosis

C. GI disorders that cause prolonged diarrhea or vomiting

Over half of the body’s magnesium is found in the ________.
A. heart
B. liver
C. bones
D. brain

C. bones

High amounts of _____, especially from supplements, can cause diarrhea.
A. magnesium
B. sodium
C. calcium
D. potassium

A. magnesium

24. Some scientists believe that vitamin D recommendation should be much higher than currently set.
A. True
B. False

A. True

Beta-carotene is also called ________.
A. provitamin A
B. retinal or retinol
C. calcitriol
D. rhodopsin

A. provitamin A

In the intestinal cells, ________. A. vitamin A, as retinal, is converted to beta-carotene B. carotenes are split by an intestinal enzyme to form vitamin A
C. excess vitamin A is carried to the kidney for excretion
D. All of these choices are correct

B. carotenes are split by an intestinal enzyme to form vitamin A

Retinal, retinol, and retinoic acid are all forms of ________.
A. vitamin A
B. vitamin K
C. vitamin D
D. vitamin E

A. vitamin A

Rhodopsin, the visual pigment in the retina of the eye, is regenerated when opsin combines with ________.
A. retinoic acid
B. 11-cis retinal
C. 13-cis-retinol
D. beta-carotene

B. 11-cis retinal

Of the following, the best source of preformed vitamin A is ________. A. fried liver
B. sautéed spinach
C. fresh mango
D. cheddar cheese

A. fried liver

Of the following, the best source of provitamin A is ________.
A. fried liver
B. baked sweet potato
C. fresh bananas
D. soybeans

B. baked sweet potato

The yellow-orange coloring of carotenoid-rich dark green vegetables is masked by the pigment ________.
A. lycopene
B. chlorophyll
C. beta-carotene
D. alpha-carotene

B. chlorophyll

Mucus-forming cells in the body deteriorate and can no longer produce mucus when there is a deficiency of ________.
A. vitamin D
B. beta-carotene
C. vitamin K
D. vitamin A

D. vitamin A

When viewing items at night or in very dim light, light strikes the retina of the eyes ________.
A. and causes the retinal to change from its cis form to its trans form
B. and splits the rhodopsin into opsin and all-trans-retinal
C. to trigger an electrical signal along the optic nerve
D. All of these choices are accurate

D. All of these choices are accurate

A deficiency of vitamin A can lead to development of a condition called ________. A. xerophthalmia
B. osteomalacia
C. jaundice
D. scurvy

A. xerophthalmia

Vitamin A deficiency is characterized by the ________. A. inability to produce insulin B. failure to form blood clots C. inability to adapt quickly to changes in light intensity D. production of excessive amounts of collagen

C. inability to adapt quickly to changes in light intensity

The maintenance of mucus-forming cells depends on adequate amounts of ________. A. vitamin D
B. vitamin C
C. vitamin A
D. vitamin K

C. vitamin A

The biochemical functions of vitamin A include all of the following except: ________. A. controlling vision in dim and bright light
B. development and maintenance of mucus-forming cells
C. cell differentiation D. coenzyme synthesis

D. coenzyme synthesis

Which statement correctly describes vitamin A? A. Vitamin A is carried from the liver by retinol-binding protein and transthyretin in the blood. B. Nearly all cells have vitamin-A binding retinoid receptors. C. Within a cell, vitamin A is involved in gene expression and cell differentiation.
D. All of these statements are correct.

D. All of these statements are correct.

Vitamin A supplements are not necessary for most adult Americans as they have significant reserves in ________. A. the eye
B. the skin
C. the kidney
D. the liver

D. the liver

The current RDA for vitamin A is expressed in ________.
A. Beta Carotene International Units (BCIU)
B. Retinol Activity Equivalents (RAE)
C. Alpha-Tocopherol Equivalents (ATE)
D. None of these answers are correct

B. Retinol Activity Equivalents (RAE)

n North America, population groups at increased risk of vitamin A deficiency include all of the following EXCEPT ________. A. college-aged diabetics B. alcoholics with liver disease C. those with GI diseases that prevent fat absorption
D. low birth weight, premature infants

A. college-aged diabetics

The most likely cause of a vitamin A toxicity would be ________.
A. consuming large amounts of dark green and yellow vegetables
B. eating sautéed liver and onions twice a week C. consuming high levels of vitamin A supplements
D. drinking carrot juice twice a day

C. consuming high levels of vitamin A supplements

itamin A toxicity is known to cause all of the following EXCEPT ________.
A. birth defects
B. permanent damage to the liver
C. kidney disease
D. death

C. kidney disease

What vitamin would most likely lead to death in both deficient and toxic levels?
A. vitamin A
B. vitamin C
C. vitamin E
D. vitamin B-12

A. vitamin A

A potential danger of using oral Accutane for acne is that it ________.
A. can cause spontaneous abortion and birth defects
B. can cause blindness if used for over a year
C. may lead to atherosclerosis D. can lead to osteomalacia

A. can cause spontaneous abortion and birth defects

Children eating large amounts of carrots can develop ________. A. hyperactivity B. hypercarotenemia C. hyperglycemia
D. vitamin A toxicity

B. hypercarotenemia

A derivative of vitamin A, 13-cis-retinoic acid (Accutane), is used to ________.
A. prevent xerophthalmia
B. treat serious cases of acne C. treat hypercarotenemia D. prevent skin cancer

B. treat serious cases of acne

Vitamin D deficiency can result in poorly mineralized bone. The resulting disease is called ________. A. osteoporosis
B. osteomalacia
C. osteoarthritis
D. osteopenia

B. osteomalacia

Healthy, light-skinned individuals can make sufficient vitamin D to meet the body’s needs with about ________ of sun exposure on their face, arms, and hands 2 or 3 times per week.
A. 15 minutes
B. 60 minutes
C. 90 minutes
D. 120 minutes

A. 15 minutes

The nutrient that can be considered both a vitamin and a hormone is vitamin ________.
A. E
B. K
C. D
D. A

C. D

Vitamin D is sometimes called the sunshine vitamin because ________.
A. it is available in fresh orange juice
B. exposure to sunlight converts a precursor form to vitamin D C. it can be destroyed by exposure to sunlight
D. it is the yellow-orange color of the sun

B. exposure to sunlight converts a precursor form to vitamin D

The main active form of vitamin D in the body is ________. A. calcitriol
B. retinal
C. cholecalciferol
D. calcitonin

A. calcitriol

Vitamin D is involved in the regulation of body levels of ________.
A. cholesterol
B. calcium
C. prothrombin
D. potassium

B. calcium

Functions of vitamin D include ________.
A. prevention of scurvy B. antioxidant activity
C. glucose regulation D. absorption of calcium

D. absorption of calcium

As calcitriol, vitamin D functions in calcium and bone metabolism by ________.
A. reducing calcium excretion by the kidney
B. regulating calcium and phosphorus absorption through the intestinal wall
C. regulating the levels of calcium and phosphorus in bones
D. All of these choices are accurate

D. All of these choices are accurate

Calcitriol is the ________. A. precursor to vitamin D that is activated by sunlight
B. plant source of vitamin D C. animal food source of vitamin D
D. biologically active form of vitamin D

D. biologically active form of vitamin D

Vitamin D deficiency in adults is called ________.
A. osteoporosis
B. osteomalacia
C. rickets
D. hypocalcemia

B. osteomalacia

In children, bowed legs, an enlarged head, rib cage, and knee joints, and a deformed pelvis are symptoms of ________. A. rickets
B. xerophthalmia
C. osteopenia
D. None of these are correct

A. rickets

A reliable food source of vitamin D is ________.
A. yellow-orange colored fruits B. dark green leafy vegetables C. whole grain breads
D. fortified milk

D. fortified milk

As calcium levels in the blood drop below normal, ____________ is released to increase the synthesis of calcitriol.
A. calcitonin
B. thyroid hormone
C. parathyroid hormone
D. secretin

C. parathyroid hormone

Vitamin D synthesis in the skin is affected by all of the following EXCEPT ________.
A. use of sunscreen
B. skin color
C. geographic location
D. All of these factors can affect vitamin D synthesis

D. All of these factors can affect vitamin D synthesis

Individuals at increased risk of vitamin D deficiency include all of the following EXCEPT ________. A. elderly adults living in nursing homes
B. dark-skinned children with limited outdoor activity
C. young adults who eat high amounts of fatty fish and fish oils D. individuals with diseases of fat-malabsorption

C. young adults who eat high amounts of fatty fish and fish oils

Which of the following is NOT a function of vitamin D?
A. Maintaining phosphorus homeostasis
B. Regulating cell cycle activity C. Promoting antioxidant activity D. Increasing immunity against infections

C. Promoting antioxidant activity

Excess intake of vitamin D ________. A. is readily excreted
B. can cause hypercalcemia C. can cause rickets
D. can cause osteomalacia

B. can cause hypercalcemia

Vitamin E is a family of compounds comprised of the ________.
A. 4 tocopherols
B. 4 tocotrienols
C. 4 triglycerides
D. 4 tocopherols and 4 tocotrienols

D. 4 tocopherols and 4 tocotrienols

Vitamin E functions to ________. A. protect cell membranes from destruction by various reducing agents
B. protect phospholipids in cell membranes from damage by free radicals
C. accept electrons, thus neutralizing the action of free radicals
D. All of these choices are accurate

D. All of these choices are accurate

A primary function of vitamin E is to serve as ________.
A. a coenzyme
B. an antioxidant
C. a hormone
D. a peroxide

B. an antioxidant

Which of the following is NOT involved in antioxidant defense? A. glutathione peroxidase
B. superoxide dismutase
C. catalase
D. hydrogen peroxide

D. hydrogen peroxide

The most nutrient-dense sources of vitamin E are ________.
A. refined grains and cereal products
B. orange-colored fruits C. vegetable oils
D. animal fats

C. vegetable oils

Vitamin E is carried to the liver and other tissues by ________. A. albumin
B. hemoglobin
C. lipoproteins
D. retinol-binding proteins

C. lipoproteins

Of the following population groups, those at lowest risk for vitamin E deficiency are ________. A. premature infants
B. the elderly
C. athletes
D. smokers

C. athletes

A high intake of vitamin E can ________.
A. interfere with vitamin K’s blood-clotting activity
B. result in lead poisoning C. inhibit copper absorption D. cause atherosclerosis

A. interfere with vitamin K’s blood-clotting activity

Which vitamin deficiency leads to hemolytic anemia?
A. vitamin A
B. vitamin D
C. vitamin E
D. vitamin K

C. vitamin E

The mineral that partly "spares" the antioxidant vitamin E is ________.
A. copper
B. selenium
C. chromium
D. iodide

B. selenium

The amount of selenium in foods ________.
A. is consistently high in plant-based foods
B. will depend on the total amount of other minerals in the food
C. depends on the type of water used to irrigate crops
D. depends on the amount of selenium in the soil where crops are grown

D. depends on the amount of selenium in the soil where crops are grown

Excessive fluoride exposure during tooth development can cause ________.
A. glucose intolerance
B. mottling of the teeth C. dermatitis
D. bleeding of the gums

B. mottling of the teeth

The fluoridation of public drinking water is ________. A. responsible for a 40% to 60% reduction in dental caries in children
B. an effective means of providing dietary selenium
C. not as effective as fluoridated toothpaste
D. mandatory in all states in the U.S

A. responsible for a 40% to 60% reduction in dental caries in children

Fluoridated water typically contains about ________.
A. 1.0 mg/8 ounces
B. 0.2 mg/8 ounces
C. 20 mg/8 ounces
D. 0.5 mg/8 ounces

B. 0.2 mg/8 ounces

The role of hydroxyfluorapatite is to ________.
A. enhance insulin sensitivity and prevent diabetes
B. prevent dental caries C. improve the rate of growth in children
D. prevent the development of anemia

B. prevent dental caries

Fluoride is typically provided by sources such as ________. A. toothpaste
B. fluoride treatments by the dentist
C. drinking water
D. All of these choices are accurate

D. All of these choices are accurate

Which of the following is associated with selenium deficiency?
A. Wilson’s disease
B. Keshan disease
C. Grave’s disease
D. Lou Gehrig’s disease

B. Keshan disease

Which of the following enzymes contains selenium?
A. glutathione peroxidase
B. superoxide dismutase
C. lysyl oxidase
D. pancrease

A. glutathione peroxidase

Formation and maintenance of collagen requires ________. A. thiamin
B. vitamin C
C. riboflavin
D. folate

B. vitamin C

Ingestion of vitamin C during meals can modestly improve absorption of ________.
A. beta-carotene
B. nonheme iron
C. vitamin B-12
D. folate

B. nonheme iron

The primary function of vitamin C in cellular metabolism is to ________.
A. synthesize collagen
B. add hydroxyl groups to the amino acid proline
C. act as nonspecific reducing agent (electron donor) D. maintain iron in its reduced form in the formation of collagen

C. act as nonspecific reducing agent (electron donor)

Which meal contains the highest amount of vitamin C?
A. Hamburger sandwich, french fries, and cola
B. Meat loaf, mashed potatoes and gravy, and diet cola
C. Baked fish with lemon, broccoli, cole slaw, and strawberries
D. Roast beef, carrots, noodles, and coffee

C. Baked fish with lemon, broccoli, cole slaw, and strawberries

The first symptom of scurvy is ________.
A. iron-deficiency anemia B. sudden hair loss
C. pinpoint hemorrhages around hair follicles
D. nerve degeneration

C. pinpoint hemorrhages around hair follicles

Physiological changes associated with scurvy (hemorrhages, joint pain, fractures) are caused by ________. A. defective collagen synthesis B. inadequate production of the hormone thyroxine
C. failure to synthesize neurotransmitters
D. impaired function of the citric acid cycle

A. defective collagen synthesis

Which group of foods provides substantial amounts of vitamin C?
A. Citrus fruits and vegetables B. Milk and dairy products C. Beef, poultry, seafood D. Breads and cereals

A. Citrus fruits and vegetables

Factors such as heat, iron, copper, and oxygen ________. A. enhance the stability of vitamin C in foods
B. destroy vitamin C in foods C. have no effect on vitamin C D. convert vitamin C from its inactive to active form

B. destroy vitamin C in foods

Scurvy is due to a deficiency of ________.
A. vitamin C
B. thiamin
C. folate
D. vitamin B-12

A. vitamin C

The RDA for vitamin C is increased by ________ mg/day for smokers.
A. 10
B. 60
C. 35
D. 1000

C. 35

The amino acids _______ and ________ are hydroxylated with the aid of vitamin C to form strong connective tissue.
A. proline; lysine
B. glutamic acid; alanine
C. threonine; methionine
D. methionine; homocysteine

A. proline; lysine

At intakes of supplemental vitamin C greater than 2 g/day, adverse effects, including _________, may occur.
A. blood in the urine and muscle weakness
B. masking of a vitamin B-12 deficiency
C. gastrointestinal bloating and diarrhea
D. All of these choices are accurate

C. gastrointestinal bloating and diarrhea

The more dense a bone is, the more brittle it will be.

false

Bone health is easily determined by a measurement of blood calcium level.

false

Retinoids play a role in embryonic development and cell differentiation

true

Carotenoid supplementation has been effective in decreasing the risk of lung cancer in smokers

false

Vitamin A deficiency can result in development of xerophthalmia in membranes of the eye.

true

Vitamin D must be hydroxylated in the liver and kidney to become biologically active.

true

Kidney disease and liver disease increase the risk of vitamin D deficiency.

true

The RDA for vitamin E was established to prevent hemolysis of red blood cell membranes

true

Adequate selenium intake may lower risk of prostate, lung, and other cancers.

true

The RDA for vitamin C is 60 mg/day or 4 ounces of orange juice a day.

false

Large doses of vitamin C in supplement form are known to prevent, cure, or diminish the symptoms of the common cold

false

The surface bone cells that dissolve bone, releasing calcium and phosphorus to the bloodstream

Osteoclast

Biochemically active bone cells that are the most numerous and that increase in number when bone becomes more dense

Osteocyte

The bone-building cells that produce collagen and add minerals

Osteoblast

A compound composed of calcium and phosphate that is deposited into the bone protein matrix to give it strength and rigidity

Hydroxyapatite

The outer dense shell of bone that makes up most skeletal mass

cortical bone