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What is the major carrier of the fat-soluble vitamins from the intestinal epithelial cell to the circulation?
a. Albumin
b. Cholesterol
c. Chylomicrons
d. Lipid-soluble binding proteins
e. Osteocalcin
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c. Chylomicrons
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Which of the following is a property of the fat-soluble vitamins?
a. Most of them are synthesized by intestinal bacteria
b. Intestinal transport occurs by way of the portal circulation
c. Deficiency symptoms may take years to develop on a poor diet
d. Toxicity risk is higher for vitamins E and K than for other fat-soluble vitamins
e. Deficiencies are more common in industrialized nations than in developing nations.
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c. Deficiency symptoms may take years to develop on a poor diet
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*If the diet contains precursor vitamin A, which of the following tissues can use it to form vitamin A?
a. Eyes
b. Kidneys
c. Adipose cells
d. Intestinal cells
e. Brain
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d. Intestinal cells
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*Which of the following food substances can be converted to vitamin A in the body?
a. Tryptophan
b. Chlorophyll
c. Xanthophyll
d. Beta-carotene
e. Phylloquinone
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d. Beta-carotene
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*How many different forms of vitamin A are active in the body?
a. one
b. two
c. three
d. five
e. seven
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c. three
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*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
e. Ergocalciferol
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c. Retinol-binding protein
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*With what vitamin is opsin usually associated in the body?
a. A
b. B1
c. C
d. D
e. K
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a. A
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*Which of the following describes an association between 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.
e. Retinol protects the visual cortex from teratogenic chemicals.
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b. Light causes retinal to shift from a cis to a trans configuration.
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*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
e. Optinal
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c. Retinal
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*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.
e. Retinal in the visual cortex responds to electrical signals from the retina.
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a. Light energy strikes the retina and excites pigments to release retinal.
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Approximately what percentage of the body’s vitamin A stores are found in the liver?
a. 20
b. 50
c. 70
d. 80
e. 90
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e. 90
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*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 remodeling to occur.
d. It inhibits oxidation of bone mucopolysaccharides, thereby preserving bone crystal integrity and promoting growth.
e. It ensures the formation of healthy bone matrix in utero.
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c. It assists enzymes that degrade certain regions of the bone, thereby allowing remodeling to occur.
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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 to 2 months
c. 6 months
d. 6 months to 1 year
e. 1 to 2 years
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e. 1 to 2 years
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Worldwide, how many preschool age children go blind each year due to vitamin A deficiency?
a. 250,000
b. 500,000
c. 750,000
d. 1,000,000
e. 1,250,000
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b. 500,000
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*Why does vitamin A status depend on the person’s protein status?
a. Adequate protein intake is a marker for liberal intake of the vitamin.
b. Dietary protein ensures synthesis of the vitamin’s GI tract transporter.
c. Adequate protein intake reduces the risk for infection from bacteria that degrade the vitamin.
d. Transport of the vitamin within the body requires sufficient protein to synthesize retinol-binding protein.
e. Protein is necessary to free the vitamin from its bonds to lipids.
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d. Transport of the vitamin within the body requires sufficient protein to synthesize retinol-binding protein.
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Studies in developing countries have demonstrated that the mortality rate of children with measles can be significantly reduced by providing supplements of
a. iron.
b. vitamin A.
c. folic acid.
d. phylloquinone.
e. vitamin E.
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b. vitamin A.
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*Vitamin A supplements are helpful in treating which of the following conditions?
a. Acne
b. Rickets
c. Osteomalacia
d. Night blindness
e. Scurvy
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d. Night blindness
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*Which of the following is a feature of vitamin A nutrition?
a. Deficiency is common in both the United States and many developing countries.
b. Toxicity occurs from excess intakes of preformed vitamin A as well as beta-carotene.
c. Supplements are recommended for certain groups of infants and children infected with the measles in the United States.
d. In poor countries, supplements prevent and cure night blindness but offer little protection against malaria and lung disease.
e. The risk of toxicity is so high that most vitamin A supplements are by prescription only.
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c. Supplements are recommended for certain groups of infants and children infected with the measles in the United States.
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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.
e. It is far safer than was once believed.
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d. It is known to cause birth defects when used by pregnant women.
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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
e. Renal damage
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c. Skin yellowing
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*Which of the following is a feature of vitamin A in foods?
a. Anthocyanin in beets masks the presence of beta-carotene.
b. Fortified margarine made from corn oil is a poor source of vitamin A.
c. Most carotenoids can be converted in the body to active vitamin A.
d. Chlorophyll in dark green leafy vegetables masks the presence of beta-carotene.
e. Plants contain retinoids but no carotenoids.
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d. Chlorophyll in dark green leafy vegetables masks the presence of beta-carotene.
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*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
e. Bananas
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b. Pumpkin pie
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*Which of the following is a characteristic of vitamin A in foods?
a. Fast foods are generally considered good sources of vitamin A.
b. Arctic explorers who have eaten large quantities of polar bear liver have become ill with symptoms suggesting vitamin A toxicity.
c. Xanthophylls in certain vegetables can be converted to active vitamin A in the liver.
d. Chlorophyll in vegetables can be converted to active vitamin A in the intestinal cells.
e. Pregnant women should eat at least one ounce of beef liver per day to help ensure normal fetal eye development.
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b. Arctic explorers who have eaten large quantities of polar bear liver have become ill with symptoms suggesting vitamin A toxicity.
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*The plant version of vitamin D is known as
a. ergocalciferol.
b. foliocalciferol.
c. cholecalciferol.
d. phyllocalciferol.
e. xanthociferol.
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a. ergocalciferol. (Vitamin D2)
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*The animal version of vitamin D is known as
a. ergocalciferol.
b. foliocalciferol.
c. cholecalciferol.
d. phyllocalciferol.
e. xanthociferol.
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c. cholecalciferol. (vitamin D3)
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*Which of the following compounds serves as the major precursor for the body’s synthesis of vitamin D?
a. Cholesterol
b. Tryptophan
c. Beta-carotene
d. Eicosapentaenoic acid
e. Histamine
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a. Cholesterol
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What percentage of the U.S. population is deficient in vitamin D?
a. 5
b. 10
c. 20
d. 30
e. 40
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b. 10
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The main function of vitamin D is to promote
a. secretion of calcitonin.
b. synthesis of 7-dehydrocholesterol.
c. synthesis of carotenoids and controls absorption of fat-soluble vitamins.
d. calcium and phosphorus absorption, and calcium mobilization from bone.
e. conversion of calcium and phosphorous to more readily absorbable compounds.
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d. calcium and phosphorus absorption, and calcium mobilization from bone.
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Where is calbindin primarily found in the body?
a. Liver
b. Kidneys
c. Intestine
d. Chylomicrons
e. Stomach
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c. Intestine
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A child with bowed legs is likely deficient in vitamin
a. A.
b. B12.
c. C.
d. D.
e. E.
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d. D.
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*What is the name of the vitamin D-deficiency disease in adults?
a. Rickets
b. Osteomalacia
c. Keratomalacia
d. Hyperkeratosis
e. Osteopenia.
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b. Osteomalacia
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*What population group is at highest risk for osteomalacia?
a. Infants
b. Elderly men
c. Adult women
d. Children ages 2-12 years
e. Whites living in tropical areas
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c. Adult women
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Which of the following may result from excessive intakes of vitamin D by adults?
a. Increased bone density
b. Increased bone calcification
c. Deformity of leg bones, ribs, and skull
d. Mineral deposits in soft tissues such as the kidney
e. Early-onset osteoarthritis
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d. Mineral deposits in soft tissues such as the kidney
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Your old friend from high school has just moved to Northern Canada to do full-time research on bats in caves. She typically works in the caves during the day when the bats are there and leaves at sundown when the bats are active. As your friend only purchases organic and all-natural foods, which of the following would you most likely advise she buy regularly at the grocery store?
a. Whole-grain bread
b. Vitamin D-fortified milk
c. Vitamin A-fortified carrot juice
d. Omega-3 fatty acid-fortified milk
e. Vitamin K-rich whole grain cereals
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b. Vitamin D-fortified milk
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*Which of the following is a feature of vitamin D?
a. The bioavailability of vitamin D from soy milk is low
b. Lifeguards on southern beaches have increased risk for vitamin D toxicity
c. Most adults living in the southern United States need small amounts of dietary vitamin D
d. The average consumption in the United States does not meet the recommended intake
e. Taking vitamin D on an empty stomach improves absorption by as much as 50%.
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d. The average consumption in the United States does not meet the recommended intake
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*Which of the following is a characteristic of vitamin D nutrition?
a. Vitamin D deficiency may be created by a calcium deficiency
b. Only about one-half of the world’s population relies on sunlight to maintain adequate vitamin D nutrition
c. Prolonged exposure to sunlight degrades the vitamin D precursor in skin, thus preventing vitamin D toxicity
d. In people living in northern U.S. cities, vitamin D stores from synthesis during the summer are usually sufficient to meet the needs during the winter
e. Pigments in dark skins increase vitamin D synthesis.
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c. Prolonged exposure to sunlight degrades the vitamin D precursor in skin, thus preventing vitamin D toxicity
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*Which of the following enables much of the world’s population to maintain adequate vitamin D status?
a. Outdoor exposure of the skin to sunlight
b. Wide availability of low-cost fish products
c. Wide availability of food assistance programs
d. World Health Organization distribution of vitamin D capsules
e. Genetically modified crops such as Golden Rice
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a. Outdoor exposure of the skin to sunlight
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Which of the following conditions is known to lead to formation of mineral deposits in the blood vessels and kidney?
a. Excessive intake of vitamin D
b. Inadequate intake of vitamin D
c. Excessive intake of tocopherols
d. Inadequate intake of tocopherols
e. Imbalances of vitamin D and tocopherols
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a. Excessive intake of vitamin D
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Which of the following is a feature of vitamin D?
a. Toxicity from vitamin D may result from overexposure to the sun.
b. Requirements are much higher in the elderly due to degenerative bone diseases.
c. Fortification of milk with the vitamin is common in order to provide people with a reliable source.
d. Absorption from most food sources is very poor, necessitating the enrichment of grain products.
e. People who stay in the shade and wear long-sleeved clothing are 10 times as likely to develop vitamin D deficiency as those who rarely do so.
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c. Fortification of milk with the vitamin is common in order to provide people with a reliable source.
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Which of the following is the most reliable source of vitamin D in the diet?
a. Meat
b. Fortified milk
c. Fruits and vegetables
d. Enriched breads and cereals
e. Whole grains
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b. Fortified milk
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Which of the following is a feature of vitamin D synthesis?
a. Tanning lamps and tanning booths do not stimulate vitamin D synthesis.
b. Sunscreens with sunburn protection factors of 2 and above prevent synthesis of vitamin D.
c. The ultraviolet rays of the sun are able to easily pierce heavy clouds and smog to promote vitamin D synthesis.
d. Dark-skinned people require longer sunlight exposure than light-skinned people to synthesize equivalent amounts of vitamin D
e. The risks of skin cancer often outweigh the benefits of sun exposure for very light-skinned people.
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d. Dark-skinned people require longer sunlight exposure than light-skinned people to synthesize equivalent amounts of vitamin D
|
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Which of the following is a naturally occurring food source of vitamin D?
a. Egg yolks
b. Red meats
c. Tomato juice
d. Whole-wheat bread
e. Egg whites
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a. Egg yolks
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What is the Recommended Dietary Allowance for vitamin D in individuals around 20 years of age?
a. 5 μg
b. 10 μg
c. 15 μg
d. 20 μg
e. 50 μg
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c. 15 μg
|
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Absorption efficiency of vitamin D supplements is markedly improved when they are taken
a. with a large meal.
b. with a small meal.
c. with orange juice.
d. on an empty stomach.
e. with milk.
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a. with a large meal.
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Which of the following vitamins has been noted as preventing the oxidation of low-density lipoproteins?
a. A
b. E
c. K
d. D2
e. D3
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b. E
|
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The main function of vitamin E in the body is to act as a(n)
a. peroxide.
b. coenzyme.
c. antioxidant.
d. free radical.
e. immune stimulant.
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c. antioxidant.
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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.
e. It enhances the inflammatory response.
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b. It slows oxidation of low-density lipoproteins.
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The major function of vitamin E is to inhibit the destruction of
a. lysosomes.
b. free radicals.
c. mucopolysaccharides.
d. polyunsaturated fatty acids.
e. monounsaturated fatty acids.
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d. polyunsaturated fatty acids.
|
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*What form of tocopherol shows vitamin E activity in the human body?
a. Alpha
b. Beta
c. Gamma
d. Delta
e. Epsilon
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a. Alpha
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*Which of the following disorders may result from vitamin E deficiency in people?
a. Rickets
b. Xerophthalmia
c. Muscular dystrophy
d. Erythrocyte hemolysis
e. Osteomalacia
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d. Erythrocyte hemolysis
|
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Which of the following is a feature of vitamin E?
a. The vitamin functions as a hormone-like substance.
b. Toxicity symptoms include bone abnormalities.
c. Deficiencies occur from inability to absorb dietary lipids.
d. Important food sources include enriched breads and pasta.
e. The RDA is based on the tocopherols and the tocotrienols.
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c. Deficiencies occur from inability to absorb dietary lipids.
|
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*Which of the following conditions may improve with vitamin E therapy?
a. Diabetes
b. Pernicious anemia
c. Muscular dystrophy
d. Intermittent claudication
e. Dementia
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d. Intermittent claudication
|
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*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
e. Very resistant to degradation
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a. Easily destroyed by air and oxygen
|
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Which of the following is a feature of vitamin E in foods?
a. Vitamin E is fairly stable to heat.
b. Most convenience foods are poor sources of vitamin E.
c. Saturated oils are the major dietary sources of vitamin E.
d. The amount of alpha-tocopherol in foods is underestimated.
e. Lean meats are better sources than fatty meats.
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b. Most convenience foods are poor sources of vitamin E.
|
|
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
e. Egg whites
|
c. Vegetable oils
|
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*Which of the following is characteristic of the tocopherols?
a. Good food sources include lean meats and dairy.
b. The various tocopherols perform similar roles in the body.
c. They are usually found in foods high in polyunsaturated fats.
d. The various tocopherol compounds can be converted to the active alpha-tocopherol.
e. The upper level for adults in 2000 mg/day.
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c. They are usually found in foods high in polyunsaturated fats.
|
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What is prothrombin?
a. A storage protein for vitamin K
b. A transport protein for vitamin E
c. A protein needed for bone formation
d. A protein needed for blood clot formation
e. A protein that decreases the "stickiness" of red blood cells
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d. A protein needed for blood clot formation
|
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In what chief capacity does vitamin K function?
a. Blood clotting
b. Energy metabolism
c. Calcium utilization
d. Epithelial tissue renewal
e. Synthesis of gonadotrophic hormones
|
a. Blood clotting
|
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Which of the following is a feature of vitamin K?
a. Vitamin K participates in metabolism of bone proteins.
b. Large amounts can be stored in adipose tissue, resulting in significant toxicity risk.
c. Good food sources are legumes and raw fruits.
d. Intestinal bacterial synthesis provides over 90% of the body’s need for most people.
e. A single oral dose is given at birth to promote blood clotting.
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a. Vitamin K participates in metabolism of bone proteins.
|
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*Which of the following is a feature of osteocalcin?
a. It activates lysosomes involved in remodeling bone.
b. It binds calcium in the GI tract to enhance absorption.
c. It requires vitamin K to bind to bone-forming minerals.
d. It works synergistically with the kidneys to reduce urinary calcium excretion.
e. It binds to vitamin K and is excreted in feces.
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c. It requires vitamin K to bind to bone-forming minerals.
|
|
Of the following, which would most readily induce a vitamin K deficiency?
a. Atrophic gastritis
b. Antibiotic therapy
c. Presence of oxalic acid in food
d. Insufficient intake of green leafy vegetables
e. High-fat, high-protein diet
|
b. Antibiotic therapy
|
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Which of the following is a characteristic of vitamin K nutrition?
a. Deficiency may lead to hemophilia.
b. Toxicity may increase risk for hemophilia.
c. Absorption is inhibited when bile production diminishes.
d. Supplements are highly effective against osteoporosis.
e. The UL is 10% above the RDA for both men and women, across all age groups.
|
c. Absorption is inhibited when bile production diminishes.
|
|
Which of the following vitamins is synthesized by intestinal bacteria?
a. A
b. C
c. D
d. E
e. K
|
e. K
|
|
Which vitamin is routinely given as a single dose to newborns?
a. Vitamin A
b. Vitamin E
c. Vitamin K
d. Vitamin B12
e. Vitamin C
|
c. Vitamin K
|
|
What population group has the highest risk for vitamin K deficiency?
a. Young adults
b. Elderly
c. Newborns
d. Teenagers
e. Middle-aged adults
|
c. Newborns
|
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Which of the following is a feature of vitamin K?
a. Deficiencies lead to intravascular clotting.
b. Major dietary sources are whole grains and legumes.
c. No adverse effects have been reported with high intakes.
d. Primary deficiencies are more common than secondary deficiencies.
e. Dietary vitamin K comes mostly from orange vegetables.
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c. No adverse effects have been reported with high intakes.
|
|
Which of the following is a major form of vitamin K in foods?
a. Ergodione
b. Ergoquinone
c. Tocopherone
d. Phylloquinone
e. Ergotamine
|
d. Phylloquinone
|
|
Approximately what percentage of the body’s store of vitamin K is derived from GI tract bacterial synthesis?
a. Less than 5
b. 25
c. 50
d. 85
e. 95
|
c. 50
|
|
Which of the following is a characteristic of free radicals?
a. They are destroyed by cigarette smoking.
b. They arise from normal metabolic reactions.
c. They typically stop chain reactions associated with the production of peroxides.
d. They are known to accumulate even in the presence of abundant antioxidant nutrients.
e. They are more common in infants and children than adults and the elderly.
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b. They arise from normal metabolic reactions.
|
|
Substances that promote oxidation are usually termed
a. prooxidants.
b. antioxidants.
c. free radical generators.
d. reactive electron oxidants.
e. oxidative facilitators.
|
a. prooxidants.
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