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152 Cards in this Set

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1. When water-soluble vitamins are consumed in excess of body needs, generally the excess is:

a. excreted in the feces.


b. stored in liver, bone, and adipose tissue.


c. excreted in the urine.


d. not absorbed.

c. excreted in the urine.
2. A major function of B vitamins is to serve as:a. antibodies.

b. a source of energy.


c. a part of a coenzyme.


d. electrolytes.

c. a part of a coenzyme.
3. Most animals synthesize their own ascorbic acid from _____.

a. glucose


b. glutamine


c. glycogen


d. alanine

a. glucose
Vitamin C acts as a cofactor by maintaining iron in a reduced state in:

a. collagen synthesis.


b. methylation of homocysteine.


c. release of energy from nutrients.


d. red blood cell synthesis.

a. collagen synthesis.
Although excess absorbed ascorbic acid is excreted in urine, the body has an estimated maximal body pool of about _____, which can be maintained with intakes of 100-200 mg vitamin C per day.

a. 500 mg


b. 1000 mg


c. 1500 mg


d. 2000 mg

d. 2000 mg
7. Which water-soluble vitamin contributes to “intracellular cement” in the formation of scar tissue and wound healing?

a. thiamin


b. riboflavin


c. vitamin C


d. vitamin B12

c. vitamin C

8. Which of the following molecules synthesized with the help of vitamin C underscores the importance of vitamin C to fat metabolism?


a. carnitine


b. collagen


c. tyrosine


d. norepinephrine

a. carnitine
9. Ascorbic acid provides a reducing equivalent so that iron is in the _____ form in lysyl hydroxylase.

a. ferric


b. ferrous

b. ferrous
10. Without enough vitamin C, collagen would _____.

a. be too tightly coiled


b. be over-hydroxylated


c. be under-hydroxylated


d. too strong and less flexible

c. be under-hydroxylated
12. Vitamin C’s actual participation in biochemical reactions usually involves its antioxidant ability. Choose the description of this activity.

a. Donates an electron or electrons to oxidize a mineral cofactor


b. Accepts an electron or electrons to reduce a mineral cofactor


c. Donates an electron or electrons to reduce a mineral cofactor


d. Accepts an electron from the quinone form of vitamin E

c. Donates an electron or electrons to reduce a mineral cofactor
13. The necessity of ascorbic acid for its role in _____ is believed to be the reason that people with scurvy have no energy and are very tired.

a. collagen synthesis


b. creatine synthesis


c. hormone activation


d. carnitine synthesis

d. carnitine synthesis
14. The RDA for vitamin C for adult men is _____ and the UL is _____.

a. 75 mg, 500 mg


b. 100 mg, 500 mg


c. 90 mg, 2000 mg


d. 200 mg, 2000 mg

c. 90 mg, 2000 mg

15. Ascorbic acid may act as a pro-oxidant by:


a. reducing ferrous iron.


b. mobilizing ferric iron from storage.


c. reacting with transferrin-bound iron.


d. reducing dehydroascorbic acid.

b. mobilizing ferric iron from storage.
16. A major role for thiamin is:

a. energy transformation.


b. blood coagulation.


c. collagen formation.


d. erythrocyte synthesis.

a. energy transformation.
17. Thiamin is important to fatty acid synthesis due to its requirement as a coenzyme for the pentose phosphate pathway enzyme _____.

a. dopamine monooxygenase


b. transketolase


c. alpha-ketoglutarate dehydrogenase


d. phenylalanine hydroxylase

b. transketolase
18. A consequence of thiamin deficiency is:

a. pellagra.


b. megaloblastic anemia.


c. beriberi.


d. rickets.

c. beriberi.
19. Erythrocyte transketolase activity is an assay to assess the status of:

a. thiamin.


b. B6.


c. riboflavin.


d. B12.

a. thiamin.
20. The most common tests of thiamin status include all the following EXCEPT:

a. static tests of urinary thiamin metabolites.


b. a static test of serum thiamin.


c. an in vitro functional test of RBC enzyme.


d. in vivo functional tests.

d. in vivo functional tests.
21. Riboflavin coenzymes remain bound to their enzymes during the oxidation-reduction reactions and the complexes are called _____.

a. apoenzymes


b. flavokinases


c. bound enzymes


d. flavoproteins

d. flavoproteins
22. Cheilosis is a symptom of a dietary deficiency of which vitamin?

a. niacin


b. ascorbic acid


c. riboflavin


d. biotin

c. riboflavin
23. When the diet is adequate in protein, the body can synthesize niacin from which amino acid?

a. phenylalanine


b. valine


c. tyrosine


d. tryptophan

d. tryptophan
24. Which vitamin has a reduced coenzyme form important for fatty acid and cholesterol synthesis that is a product of the pentose phosphate pathway?

a. niacin


b. thiamin


c. riboflavin


d. vitamin C

a. niacin
25. Which classical vitamin deficiency is known for the four Ds: dermatitis, dementia, diarrhea, and death?

a. thiamin


b. niacin


c. biotin


d. folic acid

b. niacin
26. Which of the water-soluble vitamins is found widely distributed in all plant and animal foods, which makes a deficiency unlikely?

a. riboflavin


b. folic acid


c. pantothenic acid


d. pyridoxine

c. pantothenic acid
27. Synthesis of coenzyme A starts with the phosphorylation of which vitamin?

a. pyridoxal phosphate


b. pantothenic acid


c. vitamin E


d. folic acid

b. pantothenic acid
28. Which three vitamins are involved in the synthesis of fatty acids?

a. biotin, vitamin D, thiamin


b. thiamin, riboflavin, niacin


c. niacin, biotin, pantothenic acid


d. riboflavin, B12, folate

c. niacin, biotin, pantothenic acid

. Biotin must be covalently bound to each of four different enzymes in order for them to carry out _____.


a. decarboxylations


b. oxidation-reduction reactions


c. transfer of acetate groups


d. carboxylations

d. carboxylations
30. A deficiency of what vitamin is associated with these symptoms: hallucinations, lethargy, skin rash, alopecia, and muscle pain?

a. biotin


b. thiamin


c. vitamin C


d. vitamin B12

a. biotin
31. Folate in foods can only be absorbed in the monoglutamate form; therefore, digestive enzymes called _____ are important for folate nutriture.

a. hydrolases


b. lipases


c. conjugases


d. legumes

c. conjugases
32. To absorb folate consumed from green, leafy vegetables, _____.

a. phosphate groups much be removed by the action of alkaline phosphatase


b. glutamate must be transaminated to form alpha-ketoglutarate


c. glutamic acid molecules must be removed


d. glutamic acid molecules must be added

glutamic acid molecules must be removed
33. Carbon in the one-carbon pool can be in the 5-methyl-THF form or the 5,10-methylene-THF form. Which statement is FALSE?

a. Both forms of carbon (methyl and methylene) can be used directly for thymidylate synthesis.


b. The methylene group of 5,10-methylene-THF can be oxidized to generate 5-methyl-THF and vice versa.


c. B12 is a cofactor for utilization of the methyl group in the conversion of homocysteine to methionine.


d. More than one is false.

d. More than one is false.
34. Which of the following reflects long-term folate status?

a. serum folate


b. red blood cell folate


c. homocysteine concentration in blood


d. serum methylmalonic acid

b. red blood cell folate
35. The degradation of _____ provides the majority of one-carbon groups for pyrimidine synthesis. In this process _____ is formed.

a. methionine, tetrahydrofolate


b. serine, 5,10-methylene tetrahydrofolate


c. uridine, tetrahydrofolate


d. homocysteine, 5-methyl tetrahydrofolate

b. serine, 5,10-methylene tetrahydrofolate
36. In the enzyme methionine synthase, vitamin B12 acts by accepting a _____ group from _____ and donating this group to _____ to form methionine.

a. carbon, methionine, folate


b. methyl, 5-methyltetrahydrofolate, homocysteine


c. methyl, formiminoglutamic acid, succinyl-CoA


d. carbon, serine, glycine

b. methyl, 5-methyltetrahydrofolate, homocysteine
37. Which is NOT a fate of homocysteine in the cell?

a. methylated to methionine


b. used to restore tetrahydrofolate


c. used to synthesize cysteine


d. used in the synthesis of leucine

d. used in the synthesis of leucine
38. 5-methyl THF requires the action of which vitamin in order to form THF?

a. B12


b. B2


c. niacin


d. C

a. B12
39. Elevated homocysteine levels can be due to all the following EXCEPT:

a. low ascorbic acid.


b. low folacin.


c. low cobalamin.


d. low pyridoxine.

a. low ascorbic acid.
40. Methionine is used to synthesize S-adenosylmethionine (SAM). Why is this important?

a. so that 5-methyl THF is formed


b. so that dUMP is catalyzed to dTMP


c. so that fatty acids with an odd-numbered chain can be metabolized


d. so that methyl groups are available

d. so that methyl groups are available
41. Folate is vitally important for dividing cells during growth and cancer because of its essential role in the synthesis of _____.

a. lipid bilayers


b. mitochondria


c. lysosomes and peroxisomes


d. purines and pyrimidines

d. purines and pyrimidines
42. Tetrahydrofolate is vitally important for dividing cells during growth and cancer and knowledge of this need is used in cancer treatment by giving the drug methotrexate to inhibit the enzyme _____.

a. folylpolyglutamate synthetase


b. dihydrofolate reductase


c. formimino glutamate


d. conjugase

b. dihydrofolate reductase
43. Which of the following would you find under B12-deficient conditions and the methyl trap hypothesis?

a. accumulation of 5-methylene THF


b. depletion of homocysteine


c. accumulation of THF


d. accumulation of 5-methyl THF


e. more than one of the above

d. accumulation of 5-methyl THF
44. What amount of supplemental folic acid is recommended daily for women of childbearing age in the United States?

a. 200 ug DFE


b. 400 ug DFE


c. 600 ug DFE


d. 800 ug DFE

b. 400 ug DFE
45. Intrinsic factor is required for the majority of absorption of which vitamin?

a. C


b. B6


c. B12


d. B2

c. B12
46. Vitamin B12 is absorbed in the _____.

a. duodenum


b. jejunum


c. ileum


d. colon

c. ileum
47. The normal digestion and absorption of cobalamin requires adequate protein digestion in the stomach; the presence of 2 nonenzymatic proteins: _____; and a receptor located in the _____.

a. R binders and hydrochloric acid, colon


b. pepsin and hydrochloric acid, ileum


c. R protein and intrinsic factor, ileum


d. R protein and intrinsic factor, duodenum

c. R protein and intrinsic factor, ileum
48. Which of the water-soluble vitamins is able to be stored and retained in the body for long periods of time?

a. folic acid


b. niacin


c. thiamin


d. B12

d. B12
49. Large amounts of folic acid can mask a vitamin B12 deficiency and prevent _____ from resulting. Over time the symptoms unique to a vitamin B12 deficiency will occur, and these are related to the _____.

a. microcytic anemia, muscular system


b. DNA and RNA synthesis, vascular system


c. one-carbon transfer, nervous system


d. macrocytic anemia, nervous system

d. macrocytic anemia, nervous system
50. Which vitamin is most involved in amino acid metabolism?

a. biotin


b. vitamin E


c. vitamin A


d. vitamin B6

d. vitamin B6
51. Metabolism of vitamin B6 to the primary coenzyme form, pyridoxal phosphate, requires the action of what other B vitamin?

a. GSH


b. NAD


c. THF


d. FMN

d. FMN
52. A good source of vitamin B6 is muscle meats because PLP is predominantly bound to the enzyme _____.

a. alanine aminotransferase


b. cystathionine synthase


c. glycogen phosphorylase


d. aspartic aminotransferase

c. glycogen phosphorylase
53. Vitamin B6 functions importantly in all of the following EXCEPT _____.

a. transamination of amino acids


b. synthesis of fatty acids


c. synthesis of niacin


d. glycogen breakdown

b. synthesis of fatty acids
54. Because vitamin B6 is involved in heme synthesis, a deficiency symptom is

a. hypochromic, microcytic anemia.


b. seizures.


c. hyperhomocysteinemia.


d. impaired calcium metabolism.

a. hypochromic, microcytic anemia.
55. Which of the following vitamins has a Tolerable Upper Intake Level established?

a. thiamin


b. riboflavin


c. vitamin B6


d. vitamin B12

c. vitamin B6
56. Ascorbic acid can reduce the oxidized form of vitamin E. Choose the phrase that describes this.

a. Ascorbic acid reduces the tocopheroxy radical to the quinone form; ascorbic acid is oxidized to dehydroascorbic acid.


b. Ascorbic acid reduces the hydroquinone form to the quinone form; ascorbic acid is reduced to semi-dehydroascorbic acid.


c. Ascorbic acid reduces the tochopheroxy radical to the tocopherol form; ascorbic acid is oxidized to semi-dehydroascorbate.

c. Ascorbic acid reduces the tochopheroxy radical to the tocopherol form; ascorbic acid is oxidized to semi-dehydroascorbate.
57. B6-dependent transamination reactions are important in which process?

a. glyconeogenesis


b. gluconeogenesis


c. heme synthesis


d. more than one of the above

b. gluconeogenesis
58. PLP functions as a coenzyme for _____ when alanine enters the liver. Alanine becomes its α-keto acid, _____.

a. transamination, pyruvic acid


b. transamination, α-ketoglutaric acid


c. transmethylation, histidine


d. desulfation, methioninie

a. transamination, pyruvic acid

T/F

Pellagra symptoms may appear during B6 deficiency, because this vitamin is required in the process of obtaining niacin from tryptophan

T

T/F


Water-soluble vitamins are not stored, but readily excreted—the one exception is that we can store folate in the liver

F

T/F

Pernicious anemia can be due to folate or B12 deficiency.

F

T/F


Theactive form of a vitamin is usually the form that has the greatestbioavailability.

F

T/F

The primary role of vitamin C is as a reducing agent, particularly for the mineral component of a number of enzymes that becomes oxidized following catalysis of a reaction.

T

T/F


High circulating levels of homocysteine (i.e., hyperhomocysteinemia) have been implicated in a number of pathologies including cardiovascular disease

T

The reason we use equivalents when discussing the RDA for some vitamins is that there are different forms of the vitamin that, by weight, are not equal in terms of vitamin activity—this is due to differences in absorption and/or metabolism.

T/F

T

T/F

Circulating concentrations of a vitamin typically reflect diet, whereas intracellular (e.g., RBCs, leukocytes) concentrations reflect body pools.

T

T/F

An increase in blood pyruvate and lactate levels may be due to a deficiency of riboflavin.

F

T/F

Urinaryexcretion of xanthurenic acid may be an indication of niacin deficiency

F

T/F
Biotin and B12 are both required for the synthesis of odd-chain fatty acids.

F

T/F

In the folate-dependent one-carbon pool, a carbon unit in the methyl form (i.e., 5-methyl THF) is used in the conversion of homocysteine to methionine, whereas a carbon unit in the methylene form (i.e., 5,10-methylene THF) is used in DNA synthesis.

T

T/F


Vitamin C is a good reducing agent, meaning it keeps things reduced by undergoing irreversible oxidation; thus, it must continuously be replaced by dietary sources.

F

1. Nutrients can be used to compensate for some gaps in our DNA. For example:

a. Individuals with a change in the base sequence for the phenylalanine hydroxylase gene can correct the sequence of bases by eating a lot of phenylalanine.


b. Obese individuals can lose body weight by eating fewer calories than they expend.


c. Omega-3 fatty acids can up-regulate genes encoding for fat oxidation.


d. Individuals with a polymorphism that decreases activity of a folate-metabolizing enzyme, methylene tetrahydrofolate reductase, may have more elevated plasma homocysteine than those with a normal enzyme while more folate intake can normalize plasma homocysteine for those with this polymorphism.

d. Individuals with a polymorphism that decreases activity of a folate-metabolizing enzyme, methylene tetrahydrofolate reductase, may have more elevated plasma homocysteine than those with a normal enzyme while more folate intake can normalize plasma homocysteine for those with this polymorphism.
2. How do we know that folate fortification has improved the biochemical folate status of Americans?

a. more folate is being consumed


b. Americans are more aware of folate’s importance


c. there is a decline in NTDs


d. RBC folate levels have increased

c. there is a decline in NTDs
3. A genetic polymorphism that decreases the activity of N5,N10 methylene tetrahydrofolate reductase has been identified. This would cause _____.

a. an accumulation of 5-methyl THF


b. an increase in the homocysteine concentration in the cell


c. a decreased risk for megaloblastic anemia


d. a decreased risk for heart disease

b. an increase in the homocysteine concentration in the cell
4. What is the criteria for a genetic difference to be called a “polymorphism”?

a. It has to be lethal within 6 months of life.


b. It causes a miscarriage 50% of the time.


c. More men than women have the genetic difference.


d. More than 1% of the population has the variation.

d. More than 1% of the population has the variation.
5. Folic acid fortification has _____.

a. not caused the decrease in NTDs that was expected


b. had no effect on the number of NTDs in this country


c. caused a greater decrease in NTDs than was expected


d. reduced the number of various NTDs by 11% to 50% in different studies

d. reduced the number of various NTDs by 11% to 50% in different studies
1. Which of the carotenoid pigments has the greatest vitamin A activity?

a. alpha-carotene


b. beta-carotene


c. gamma-carotene


d. delta-carotene

b. beta-carotene
2. Choose the food that is high in vitamin A palmitate.

a. spinach


b. liver


c. carrots


d. pumpkin

b. liver
6. Formation of retinol from beta-carotene requires the presence of what B vitamin?

a. ascorbic acid


b. folic acid


c. niacin


d. pyridoxal phosphate

c. niacin
7. What happens to retinal in the enterocyte?

a. it is esterified


b. it is reduced to retinol


c. it is transported into the portal blood


d. 15, 15’ dioxygenase acts to form beta-carotene

a. it is esterified
8. Choose the ONE correct statement.

a. Beta-carotene is hydrolyzed in the jejunum before it is absorbed.


b. Retinol does not need to form a micelle to cross the USW.


c. Beta-carotene dioxygenase activity occurs in the lumen of the ileum.


d. Retinol must be re-esterified to be carried in the chylomicron.

d. Retinol must be re-esterified to be carried in the chylomicron.
9. In order to be carried in the chylomicron, retinol (once in the enterocyte) is _____.

a. esterified by lecithin retinol acyl transferase


b. converted to retinaldehyde by retinaldehyde reductase


c. attached to a VLDLd. attached to an RXR receptor on the nucleus


d. attached to an RXR receptor on the nucleus

a. esterified by lecithin retinol acyl transferase
10. The majority of vitamin A is stored in the liver, while carotenoids are stored mainly in the _____ tissue.

a. muscle


b. eye


c. adipose


d. skin

c. adipose
11. In what cells will you find most of the retinol and vitamin A stored?

a. stellate


b. gallbladder


c. fundus


d. antrum

a. stellate
12. How will retinol, once secreted from the liver, be found in the blood?

a. attached to RBP and transthyretin


b. attached to albumin


c. attached to a chylomicron


d. attached to RBP and stellate cells

a. attached to RBP and transthyretin
13. Which of the following is needed for the visual cycle?

a. 11-cis retinal


b. 9-cis retinoic acid


c. lycopene


d. cryptoxanthin

a. 11-cis retinal
17. Within the nucleus, all trans-retinoic acid and/or 9-cis retinoic acid binds to _____.

a. nuclear retinoic acid receptors


b. mannosylated glycoproteins


c. cell aggregates


d. transcription factors

a. nuclear retinoic acid receptors
18. Why is retinoic acid considered a hormone?a. It has receptors on the nucleus and causes a change in protein synthesis.

b. It has a biologic function similar to insulin.


c. It is synthesized in the same tissue that it affects.


d. It causes the catabolism (break down) of body proteins.

a. It has receptors on the nucleus and causes a change in protein synthesis.
19. Which vitamin directs cellular differentiation of epithelial cells?

a. riboflavin


b. vitamin K


c. vitamin E


d. vitamin A

d. vitamin A
20. Where would you find retinoid X receptors (RXR)?

a. cytosol


b. nucleus


c. mitochondria


d. none of the above

b. nucleus
21. Which vitamin is said to be essential for growth and immune system function?

a. K


b. A


c. D


d. E

b. A
22. Which is NOT related to the functions of vitamin A?

a. neurological function


b. growth


c. immunity


d. cell differentiation

a. neurological function
23. Choose the correct statement about the quenching of singlet oxygen by carotenoids.

a. Carotenoids donate an electron to the singlet oxygen to make it stable.


b. Carotenoids covalently bond with the singlet oxygen to make it stable.


c. Carotenoids donate energy so that the excited electron returns to its orbital.


d. Carotenoids absorb the extra energy that is held by the singlet oxygen.

d. Carotenoids absorb the extra energy that is held by the singlet oxygen.
24. Which is the strongest antioxidant?

a. beta-carotene


b. alpha-tocopherol


c. beta-cryptoxanthin


d. lycopene

d. lycopene
25. Would you recommend β-carotene supplementation to a smoker to decrease risk to lung cancer?

a. Yes—β-carotene can quench singlet oxygen.b. Yes—smoking increases free radical formation; β-carotene can decrease free radicals.


c. No—β-carotene supplements may be harmful to smokers and are their use is not advised for the general public.


d. No—β-carotene supplements can cause a vitamin A toxicity and liver cirrhosis.

c. No—β-carotene supplements may be harmful to smokers and are their use is not advised for the general public.
26. Choose thephrase which best explains the following statement: “β-carotene is no magicbullet.”

a. β-carotene does not decrease the reactivityof singlet oxygen molecules.


b. β-carotene is not the only health-promotingmolecule in fruits and vegetables.c. β-carotene supplements cannot bemanufactured cheaply enough.


d. β-carotene can replace vitamin E interminating the auto-oxidation of fatty acids.

b. β-carotene is not the only health-promoting molecule in fruits and vegetables.
27. Which micromineral deficiency interferes with vitamin A metabolism by reducing retinol-binding protein?

a. manganese


b. zinc


c. selenium


d. iron

b. zinc
28. Which symptom of a vitamin A deficiency is most likely responsible for deficiency-related deaths?

a. its function as a teratogen


b. poor cellular differentiation and growth


c. keratinization of the cornea


d. severe infections

d. severe infections
29. An individual with poor vitamin A status would have a _____ RDR than someone with a good vitamin A status.

a. greater


b. lesser

a. greater
30. Which is the best technique to assess status of vitamin A liver stores?

a. serum retinol levels


b. the relative dose response


c. clinical eye examinations

b. the relative dose response
31. Imagine you are a nutritionist working in a country other than the U.S. Which is an assumption about vitamin D status that is NOT true?

a. The latitude makes a difference as regards how much vitamin D can be self-synthesized.b. Customs of dress make a difference as regards how much vitamin D can be self-synthesized.


c. Cow’s milk is a reliable source of vitamin D in the food supply.


d. Skin color makes a difference as regards how much sun is needed to synthesize vitamin D.

c. Cow’s milk is a reliable source of vitamin D in the food supply.
32. Which vitamin D molecule would you expect to see in fortified foods?

a. ergocalciferol – vitamin D2


b. calcidiol – 25-OH D3


c. calcitriol – 1,25-OH2 D3


d. cholecalciferol – vitamin D3

d. cholecalciferol – vitamin D3
33. It’s a good thing that milk is fortified with vitamin D so that we can consume the RDA if we drink the recommended number of glasses of milk each day. The DRI for 9-69 year olds is 600 IU (15 g). This equals _____ cups of milk.

a. two


b. three


c. four


d. six

d. six
34. What % of vitamin D from the diet is absorbed?

a. 20


b. 30


c. 40


d. 50

d. 50
35. Dietary cholecalciferol must be further hydroxylated in order to be active vitamin D. The first hydroxylation occurs in the _____ to produce _____.

a. liver, 25-hydroxycholecalciferol


b. kidney, 25-hydroxycholecalciferol


c. skin, 7-dehydrocholesterol


d. kidney, 1-hydrocholesterol

a. liver, 25-hydroxycholecalciferol
36. What form of vitamin D is the major circulating form with a half-life of approximately 3 weeks?

a. calcidiol


b. calcitriol


c. cholecalciferol


d. vitamin D2

a. calcidiol
37. Which vitamin is believed to functionlike a steroid hormone?

a. choline


b. vitamin A


c. vitamin D


d. vitamin E

c. vitamin D
38. Choose the non-genomic effect of vitamin D.a. increased synthesis of calbindin

b. bone accretion


c. rapid calcium absorption


d. intracellular cytosolic signal transduction

d. intracellular cytosolic signal transduction
39. The vitamin D response element (VDRE) is found

a. on the enterocyte membrane.


b. on the renal tubule.


c. in the nucleus.


d. in the pancreatic duct cell.

d. in the pancreatic duct cell.
40. Which vitamin has as its primary function the maintenance of calcium homeostasis?

a. A


b. D


c. E


d. K

b. D
41. Choose the correct order of the phrases below to explain the response of the body to a decline in serum calcium levels. Choose the BEST answer.

1. Increased release of PTH


2. Decreased release of PTH




a. 1, 5, 4, 8


b. 1, 3, 5, 9


c. 2, 3, 9, 6


d. 1, 4, 3, 6



d. 1, 4, 3, 6
42. What vitamin is associated with diminished proliferation and enhanced differentiation of cells, which serves as a basis for its use as treatment of skin diseases such as psoriasis?

a. A


b. E


c. K


d. D

d. D
43. The RDA for vitamin D for people over the age of 70 is _____ the RDA for teenagers.

a. greater than


b. less than


c. equal to

a. greater than

44. If asked about the relationship of vitamin D to autoimmune disease, the best information for a dietetic professional to provide is:

a. the evidence does not support a relationship at this time.


b. the evidence is only in animals, not humans.c. some evidence suggests a protective effect of vitamin D.


d. take a supplement containing 2000 IU vitamin D each day.

c. some evidence suggests a protective effect of vitamin D.
45. A deficiency of which vitamin is commonly associated with rickets?

a. A


b.D


c. E


d. K

b.D
46. Toxicity of which vitamin is related to increased deposition of calcium in soft tissues?a. lipoic acid

b. biotin


c. D


d. E

c. D
47. What is a symptom of a vitamin D toxicity?

a. hypercalcemia


b. hypocalcemia


c. rickets


d. osteoporosis

a. hypercalcemia
48. Sun exposure does not cause hypervitaminosis D because _____.

a. cutaneous production of the vitamin reaches a maximum


b. sunburned skin is not sensitive to the UV wavelength that causes previtamin D3 synthesis


c. inactive products are synthesized from pre-vitamin D3 and D3


d. vitamin D-binding protein is not saturated with D3

a. cutaneous production of the vitamin reaches a maximum
49. In assessing the vitamin D status of an individual, which measure would you use?

a. circulating 25-OH cholecalciferol


b. circulating 1,25-OH2 cholecalciferol


c. circulating cholecalciferol


d. serum calcium levels

a. circulating 25-OH cholecalciferol
50. Which tocopherol form provides the most vitamin E activity in the U.S. food supply?

a. alpha


b. beta


c. gamma


d. delta

a. alpha
51. How does alpha-tocopherol differ from beta-tocopherol?

a. saturation of side chain


b. location of methyl groups


c. source in the diet

b. location of methyl groups
52. Who discovered vitamin E?

a. Evans and Bishop


b. McCollum and Davis


c. Mellanby and Hopkins


d. Simon and Garfunkel

a. Evans and Bishop
53. A genetic deficiency in _____ leads to a vitamin E deficiency syndrome.

a. RRR alpha-tocopherol


b. gamma-tocotrienol


c. tocopherol carrier protein in the jejunum


d. alpha-tocopherol transfer protein in the liver

d. alpha-tocopherol transfer protein in the liver
54. Immediately following a balanced meal that contained vitamin E (such as fortified milk), where would you most likely find most of the vitamin E in the body?

a. in the portal blood as α-tocopherol


b. in the general circulation bound to RBC


c. inside cells as free α-tocopherol


d. stored in adipose tissue


e. in chylomicrons in the lymphatic vessels and general circulation

e. in chylomicrons in the lymphatic vessels and general circulation
55. In what type of tissue is the largest amount of vitamin E stored?

a. adipose


b. heart


c. lung


d. brain

a. adipose
56. Which fat-soluble vitamin has as its principal function the maintenance of membrane integrity?

a. vitamin D


b. vitamin E


c. vitamin A


d. vitamin K

b. vitamin E
57. Which vitamin is associated with improved plasma membrane structure and glucose transport/metabolic control in people with type 2 diabetes?

a. A


b. D


c. E


d. K

c. E
58. For which vitamin is the Tolerable Upper Intake Level set because of increased tendency for bleeding?

a. A


b. D


c. E


d. K

c. E
59. Which of the fat-soluble vitamins is consumed in the form of phylloquinone from plant foods?

a. A


b. D


c. E


d. K

d. K
60. Which fat-soluble vitamin appears to operate as a coenzyme that modifies proteins to bind with calcium?

a. A


b. β-carotene


c. E


d. K

d. K
61. The action of vitamin K is the post-translational synthesis of blood clotting factors occurs:

a. in the blood.


b. in the liver.


c. in the small intestine.


d. in the bone marrow.

b. in the liver.
62. Anticoagulant drugs that act by inhibiting vitamin K activity do so by which mechanism?

a. inhibiting the formation of the active form of vitamin K


b. interfering with micelle formation so vitamin K is not absorbed


c. not allowing calcium to interact with Gla residues


d. stimulating osteocalcin synthesis

a. inhibiting the formation of the active form of vitamin K
63. Mr. S. takes warfarin due to his valve replacement surgery. He is an avid gardener and enjoys eating the many green leafy vegetables he grows. You caution Mr. S. to tell his physician about this because the amount of warfarin he takes may need to be _____

a. decreased


b. increased

b. increased
64. Risk of vitamin K deficiency is greatest in:

a. newborns


.b. children.


c. adolescents.


d. older people.

a. newborns
65. Vitamin K deficiency in adults is most likely due to:

a. oxalic acid in food.


b. achlorhydria.


c. antibiotic therapy.


d. a high-fiber diet.

d. a high-fiber diet.
66. For which vitamin is a severe deficiency associated with an increased tendency for bleeding?

a. A


b. D


c. E


d. K

d. K
67. Which is the best measure of vitamin K status?

a. des-γ-carboxyglutamic prothrombin


b. prothrombin time


c. INR


d. PTH concentration

b. prothrombin time
68. Induction of a protein (i.e., increasing the amount of a protein) via increasing gene expression can be accomplished by:

a. vitamin A.


b. folate.


c. vitamin C.


d. more than one of these vitamins

a. vitamin A.

T/F


Gutbacteria can produce some vitamins, but this rarely contributes to ourrequirements because they are not absorbed.

F

Becauseβ-carotene can be converted into retinol, plant sources are referred to aspreformed vitamin A.

T/F

F

T/F


Production of active vitamin D requires skin, sunlight, cholesterol, the liver, and the kidneys.

T

Calcium homeostasis in the blood depends on intestinal absorption, bone resorption, and kidney reabsorption.

T/F

T

Many anticoagulants inhibit the vitamin K cycle, thereby preventing activation of clotting proteins.



T/F

T

T/F


All three forms of vitamin A (retinol, retinal, retinoic acid) are stored in the liver as retinyl esters

F

T/F


Vitamin D increases the abundance of calbindin (Ca++ transporter) in enterocytes by increasing the transcription of the calbindin gene.

T

Rhodopsin is simply the opsin protein after it has been activated by 11-cis-retinal.



T/F

T

Many anticoagulants work by inhibiting the regeneration of active vitamin K (i.e., dihydrovitamin KH2) during the vitamin K cycle

T/F

T

T/F


All of the functions of vitamin A are carried out by retinoic acid via transcriptional mechanisms.

F

Agood source of vitamin D is milk, because it is fortified with 1,25-(OH)2-vitaminD3.

T/F

F

7-dehydrocholesterol is the form of vitamin D that is added to fortify milk.

T/F

F

1. Free radicals take electrons from all of the following EXCEPT _____.

a. calcitriol


b. DNA


c. proteins


d. PUFAs

a. calcitriol
2. Which antioxidant is most effective in rapidly eliminating hydroxyl radicals prior to initiation of oxidative damage?

a. vitamin E


b. vitamin C


c. vitamin K


d. beta-carotene

b. vitamin C
3. Which antioxidant is most effective in terminating chain-propagation reactions in cell membranes?

a. vitamin E


b. vitamin C


c. vitamin K


d. beta-carotene

a. vitamin E
4. The current thought about using antioxidant supplements to decrease risk to cancer and heart disease is:
a. more is better.

b. eat antioxidant-rich foods instead.


c. vitamin E supplements work; β-carotene does not.


d. only vitamin C has much promise.

b. eat antioxidant-rich foods instead.