Deck 12: The Antioxidant Nutrients

Question 1

If a normal, healthy adult were to begin consuming a vitamin A-poor diet, approximately how much time would pass before the first deficiency symptoms would appear?

A) 2 weeks
B) 1-2 months
C) 6 months
D) 1-2 years

Answer 1

D

Question 2

Approximately how many children worldwide have vitamin A deficiency?

A) 5 million
B) 25 million
C) 250 million
D) 500 million

Answer 2

C

Question 3

Greg says that he usually eats 1 medium carrot every day to ensure that he's consuming enough vitamin A. Today he said he didn't eat any carrots and is worried that there is not enough vitamin A in his system. Which of the following would you say to Greg to allay his fear?

A) "Take a vitamin A supplement as soon as you can!"
B) "As long as you eat some chicken tonight you will not develop any deficiency."
C) "Well, there isn't any vitamin A in carrots so you probably haven't consumed vitamin A for some time now."
D) "Don't worry; fat-soluble vitamins are stored in the body. It takes a lot longer than one day to develop any adverse effects."

Answer 3

D

Question 4

Which of the following is a form of vitamin A?

A) retinol
B) cortisol
C) beta-carotinol
D) retinoquinone

Question 5

Which of the following food substances can be converted to vitamin A in the body?

A) tryptophan
B) chlorophyll
C) xanthophyll
D) beta-carotene

Question 6

Which of the following describes the primary function of vitamin A in bone health?

A) It stimulates uptake of calcium from the intestines.
B) It promotes synthesis of specific bone proteins involved in the mineralization process.
C) It assists enzymes that degrade certain regions of the bone thereby allowing remodelling to occur.
D) It inhibits oxidation of bone mucopolysaccharides thereby preserving bone crystal integrity and promoting growth.

Question 7

How many million molecules of vitamin a-containing visual pigments are found in the retina?

A) 30
B) 40
C) 50
D) 60

Question 8

Why does vitamin A status depend on the person's protein status?

A) Adequate protein intake is a marker for liberal intake of vitamin A.
B) Dietary protein assures synthesis of vitamin A's GI tract transporter.
C) Adequate protein intake reduces the risk for infection from bacteria that degrade vitamin A.
D) Transport of vitamin A within the body requires sufficient protein to synthesize retinol-binding protein.

Question 9

Which of the following describes an association of vitamin A and vision?

A) Retinoic acid is the form required for synthesis of retinoblasts.
B) Light causes retinal to shift from a cis to a trans configuration.
C) Retinol is the form bound to beta-carotene in the corneal membrane.
D) Pigment molecules in the retina are composed of a molecule of vitamin A bound to an omega-3 fatty acid.

Question 10

Which vitamin works with vitamin A to protect the body's cells from oxidative damage?

A) C
B) B₁₂
C) D
D) E

Question 11

Which of the following tissues can use precursor vitamin A to form vitamin A?

A) pancreatic cells
B) red blood cells
C) adipose cells
D) intestinal cells

Question 12

What tissue contains the majority of the body's store of vitamin A?

A) liver
B) adipose
C) retinal cells
D) intestinal mucosal cells

Question 13

Which of the following is the name of the vitamin A compound that is active in the visual response?

A) opsin
B) keratin
C) retinal
D) carotene

Question 14

What is the name of an atom with an unpaired electron?

A) free atom
B) radical electron
C) free radical
D) radical electron

Question 15

What are the known effects of raising animals on diets containing retinoic acid as the only source of vitamin A?

A) Growth is stunted.
B) Blindness develops.
C) Retinal synthesis is stimulated
D) Retinol synthesis is stimulated.

Question 16

Which of the following describes an event in the visual response process?

A) Light energy strikes the retina and excites pigments to release retinal.
B) Light energy strikes the cornea and excites pigments to release retinoic acid.
C) Visual pigments deep in the brain are excited by light transmitted through the retina.
D) Epithelial cells on the surface of the eye respond to light energy by transmitting opsin molecules along nerve pathways to the brain.

Question 17

Which of the following is responsible for transporting vitamin A from the liver to other tissues?

A) albumin
B) rhodopsin
C) retinol-binding protein
D) transcarotenoid protein

Question 18

How many different forms of vitamin A are active in the body?

A) 1
B) 2
C) 3
D) 5

Question 19

Approximately what percent of the body's vitamin A stores are found in the liver?

A) 20 percent
B) 50 percent
C) 70 percent
D) 90 percent

Question 20

Approximately what percentage of Canadians fails to consume the recommended number of fruits and vegetables?

A) 50 percent
B) 55 percent
C) 60 percent
D) 65 percent

Question 21

Which of the following is a characteristic of excess consumption of beta-carotene?

A) Overconsumption prevents birth defects.
B) Overconsumption from supplements is harmless.
C) Drinking alcohol worsens the adverse effects of supplements.
D) Massive doses decrease the incidence of acne.

Question 22

On average, 1 retinol activity equivalent is equal to about how many international units?

A) 3 IU
B) 5 IU
C) 8 IU
D) 10 IU

Question 23

Which of the following is a feature of Accutane?

A) It is effective in treating rickets.
B) It is less toxic than pure vitamin A.
C) It is known to be effective in treating mild but not severe acne.
D) It is known to cause birth defects when used by pregnant women.

Question 24

Why shouldn't a 7-month pregnant woman be prescribed Accutane?

A) It may aggravate existing edema.
B) It may lead to prolongation of labour.
C) It is a teratogen and can be harmful to the baby.
D) It contains high concentrations of vitamin D that can cause birth defects.

Question 25

Which of the following features are shared by Retin-A and Accutane?

A) They are teratogenic.
B) They are highly toxic.
C) They are usually taken orally.
D) They have chemical structures similar to vitamin A.

Question 26

Which of the following is the most likely side effect for a person who regularly consumes large quantities of carrots or carrot juice?

A) bone pain
B) dermatitis
C) skin yellowing
D) vitamin A toxicity

Question 27

What population group is most vulnerable to vitamin A toxicity?

A) children
B) adolescents
C) adults
D) elderly

Question 28

Studies in developing countries have demonstrated that the mortality rate of children with measles can be significantly reduced by providing which of the following supplements?

A) iron
B) vitamin A
C) folic acid
D) phylloquinone

Question 29

Which of the following is a carotenoid which has shown positive effects with reducing risk for prostate cancer?

A) beta-carotene
B) alpha-carotene
C) zeaxanthin
D) lycopene

Question 30

Which of the following is associated with the condition known as xerosis?

A) toxicity of vitamin K
B) toxicity of beta-carotene
C) deficiency of vitamin A
D) deficiency of vitamin D

Question 31

Which of the following is a feature of taking high-dose supplements of vitamin A?

A) They increase teratogenic risk.
B) They are effective in treating acne.
C) They lead to keratinization of tissue
D) They reduce risk for neural tube defects

Question 32

How many micrograms of dietary beta-carotene are equivalent to 1 retinol activity equivalent?

A) 2 µg
B) 4 µg
C) 8 µg
D) 12 µg

Question 33

What part of the body is affected most by keratomalacia?

A) bone
B) liver
C) cornea
D) immune cells

Question 34

What is the first detectable sign of vitamin A deficiency?

A) xerosis
B) xerophthalmia
C) night blindness
D) corneal keratinization

Question 35

What is the name of the colour pigment which has no vitamin A activity and is red and yellow in colour?

A) xanthophyll
B) chlorophyll
C) anthocyanin
D) betalains

Question 36

Which of the following is most likely to occur from a prolonged dietary deficiency of vitamin A?

A) osteomalacia
B) osteoporosis
C) xerophthalmia
D) prolonged blood-clotting time

Question 37

What causes keratinization?

A) toxicity of vitamin A
B) toxicity of vitamin D
C) deficiency of vitamin A
D) deficiency of vitamin D

Question 38

In which of the following population groups are the effects of vitamin A deficiency most severe?

A) adults
B) elderly
C) preschool children
D) adolescents

Question 39

What is the preferred unit of expression of vitamin A?

A) milligram
B) global unit
C) international unit
D) retinol activity equivalent

Question 40

Which of the following conditions may keratinization of lung cells?

A) toxicity of vitamin A
B) toxicity of beta-carotene
C) deficiency of vitamin A
D) deficiency of vitamin D

Question 41

Recently, there has been a lot of news about the importance of antioxidants in the diet. Which of the following vitamins has been noted as preventing the oxidation of low-density lipoproteins?

A) vitamin A
B) vitamin E
C) vitamin K
D) vitamin D

Question 42

Which of the following features do vitamins C and E share?

A) Both function as antioxidants.
B) Both require bile for absorption.
C) Neither participates in protein synthesis.
D) Neither is affected by the processing of foods.

Question 43

George wants to try a new leafy green vegetable in his salad. Which green, that is an excellent source of beta-carotene, would you suggest to George?

A) romaine lettuce
B) iceburg lettuce
C) spinach
D) arugula

Question 44

Which of the following provides the least amount of precursor vitamin A?

A) corn
B) spinach
C) carrots
D) cantaloupe

Question 45

Which one of the following organs regulates vitamin E concentrations?

A) heart
B) kidneys
C) liver
D) pancreas

Question 46

Which of the following is a characteristic of carotenoids in foods?

A) Most carotenoids can be converted to vitamin A.
B) The carotenoid with the highest conversion rate to vitamin A is lycopene.
C) Carotenoid absorption efficiency from salads is higher when regular dressing is used compared with low-fat dressing.
D) Carotenoid absorption is masked by foods rich in chlorophyll.

Question 47

How is vitamin E thought to play a role in reducing the risk of heart disease?

A) It inhibits absorption of dietary cholesterol.
B) It slows oxidation of low-density lipoproteins.
C) It interferes with cholesterol synthesis by the liver.
D) It speeds removal of blood cholesterol by the liver.

Question 48

Which of the following foods is a very good source of vitamin A?

A) corn
B) pumpkin pie
C) baked potato
D) whole-grain bread

Question 49

Which of the following is a chronic symptom for vitamin A?

A) headaches
B) reduced bone density
C) muscle incoordination
D) vertigo

Question 50

Which of the following is likely to induce vitamin A toxicity in adults?

A) eating beef liver once a month
B) consuming high-dose vitamin A supplements
C) drinking 2 quarts of vitamin A-fortified milk daily
D) consuming large amounts of dark green and deep orange vegetables

Question 51

What is the approximate adult RDA for vitamin A?

A) 400 mg
B) 1000 mg
C) 800 retinol activity equivalents
D) 5000 retinol activity equivalents

Question 52

The major function of vitamin E is to inhibit the destruction of which of the following?

A) lysosomes
B) free radicals
C) mucopolysaccharides
D) polyunsaturated fatty acids

Question 53

A person seeking good sources of vitamin A should avoid which one of the following foods?

A) liver
B) bananas
C) apricots
D) sweet potatoes

Question 54

What form of tocopherol shows vitamin E activity in the human body?

A) alpha
B) beta
C) gamma
D) delta

Question 55

As a dietitian, you are working on ways to improve the nutritional status of children in Indonesia. You discover that many of the children and some adults suffer from night blindness. Which of the following foods would you recommend be incorporated into the Indonesian diet to help prevent future generations from developing this condition?

A) sweet potato
B) orange juice
C) peanut butter
D) powdered skim milk

Question 56

What colour does the skin turn when an individual suffers from hypercarotenemia?

A) purple
B) orange
C) yellow
D) red

Question 57

Which of the following is considered to be an unusual food source of vitamin A?

A) kefir
B) tofu
C) shrimp
D) beef liver

Question 58

In which of the following individuals would vitamin A toxicity be most likely to occur?

A) adolescent women
B) overweight adults
C) those taking vitamin A supplements
D) those consuming more than 100 g of carrots daily

Question 59

What is the role of vitamin E in the metabolism of free radicals?

A) carrier
B) promoter
C) eliminator
D) synthesizer

Question 60

What is the main function of vitamin E in the body?

A) acts as a peroxide
B) acts as a coenzyme
C) acts as an antioxidant
D) acts as a free radical

Question 61

Which of the following is a property of the tocopherols?

A) easily destroyed by air and oxygen
B) act as precursors for the menaquinones
C) may dissolve from foods into cooking water
D) absorbed from the intestines into the portal circulation

Question 62

Which of the following are major sources of vitamin E in the diet?

A) meats
B) citrus fruits
C) vegetable oils
D) milk and dairy products

Question 63

Which of the following is the reason why vitamin C supplements might be beneficial in treating the common cold?

A) They deactivate histamine.
B) They reduce episodes of diarrhea.
C) They destroy intestinal pathogens.
D) They alter hypothalamic control of body temperature.

Question 64

Which of the following contains the highest concentration of vitamin E?

A) butter
B) carrots
C) milk fat
D) wheat germ oil

Question 65

The current RDA for vitamin E is based on which form of tocopherol?

A) betaµg
B) gamma
C) delta
D) alpha

Question 66

An extremely high dose of vitamin E may interfere with the action of vitamin K, causing which of the following problems?

A) heart disease
B) dysentery
C) hemorrhage
D) nausea

Question 67

Which of the following describes a free radical?

A) an inactive vitamin
B) an unphosphorylated vitamin
C) a molecule of unbound cobalamins
D) a molecule with at least one unpaired electron

Question 68

Which factor should you multiply by to convert the number of tocopherol equivalents to alpha-tocopherol?

A) 0.8
B) 0.6
C) 0.4
D) 0.2

Question 69

In comparison with the RDA for vitamin E, about how many times higher is the Tolerable Upper Intake Level?

A) 2 times
B) 10 times
C) 25 times
D) 65 times

Question 70

Which of the following conditions may improve with vitamin E therapy?

A) diabetes
B) pernicious anemia
C) muscular dystrophy
D) intermittent claudication

Question 71

Which of the following is a characteristic of vitamin C?

A) antiviral agent
B) antifungal agent
C) anticancer agent
D) antioxidant agent

Question 72

Which of the following proteins requires ascorbic acid for its formation?

A) keratin
B) albumin
C) collagen
D) serine

Question 73

Which of the following disorders may result from vitamin E deficiency in people?

A) rickets
B) xerophthalmia
C) muscular dystrophy
D) erythrocyte hemolysis

Question 74

Which one of the following fat malabsorption diseases is associated with vitamin E deficiency?

A) Crohn's disease
B) Whipple's disease
C) cystic fibrosis
D) diabetes

Question 75

Why are vitamin E deficiencies rarely observed in human beings?

A) The vitamin is not essential.
B) The vitamin is widespread in foods.
C) Most people take vitamin E supplements.
D) The vitamin can be synthesized by the body.

Question 76

Which of the following vitamins is known to deactivate histamine, a substance that causes nasal congestion?

A) niacin
B) vitamin E
C) vitamin C
D) vitamin B₁₂

Question 77

Increasing the amount of polyunsaturated fats in the diet increases the need for which vitamin?

A) vitamin A
B) vitamin E
C) vitamin K
D) vitamin D

Question 78

In which of the following capacities does vitamin C function?

A) coenzyme for energy release
B) cofactor in collagen formation
C) cofactor with calcium in blood coagulation
D) coenzyme in the formation of red blood cells

Question 79

Which of the following represents the results of well-controlled studies of vitamin C supplementation on the resistance to, and recovery from, colds?

A) There was a reduction in the duration of colds by 50 percent on the average.
B) There was only a minor effect on reducing the number and severity of colds.
C) There was a slight, but consistent, reduction in the duration of colds in people who consumed at least 200 g a day.
D) There was a significant reduction in the number of colds only in people who consumed more than 3 g per day.

Question 80

Which one of the following diseases may respond to vitamin E treatment?

A) Parkinson's disease
B) fibrocystic breast disease
C) periodontal disease
D) Lou Gehrig's disease