question

What is the major carrier of the fat-soluble vitamins from the intestinal epithelial cell to the circulation?

answer

Chylomicrons

question

Which of the following is a property of the fat-soluble vitamins?

answer

Deficiency symptoms may take years to develop on a poor diet

question

If the diet contains precursor vitamin A, which of the following tissues can use it to form vitamin A?

answer

Intestinal cells

question

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

answer

Beta-carotene

question

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

answer

3

question

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

answer

Retinol-binding protein

question

As far as is known, vitamin A does not play an important role in which of the following processes?

answer

Blood clotting

question

Retinol-binding protein is required to transport vitamin

answer

A

question

What form of vitamin A supports reproduction but not growth?

answer

Retinol

question

What form of vitamin A supports vision but not growth?

answer

Retinal

question

What do retinal and unsaturated fatty acids have in common?

answer

They may exist in the cis or trans form

question

With what vitamin is opsin usually associated in the body?

answer

A

question

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

answer

Blindness develops

question

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

answer

Light causes retinal to shift from a cis to a trans configuration

question

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

answer

Retinal

question

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

answer

Light energy strikes the retina and excites pigments to release retinal

question

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

answer

90

question

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

answer

Liver

question

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

answer

It assists enzymes that degrade certain regions of the bone, thereby allowing remodeling to occur

question

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?

answer

1 to 2 years

question

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. What would you say to Greg to allay his fear?

answer

"Don't worry; fat-soluble vitamins are stored in the body. It takes a lot longer than one day to develop any adverse effects."

question

Which of the following vitamins is most associated with promoting synthesis of gastrointestinal mucus?

answer

A

question

What do beta-carotene and vitamin E have in common?

answer

Both act as antioxidants

question

Approximately how many children worldwide have vitamin A deficiency?

answer

250 million

question

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

answer

Transport of the vitamin within the body requires sufficient protein to synthesize retinol-binding protein

question

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

answer

vitamin A

question

Which of the following functions is shared by beta-carotene and vitamin E?

answer

Inhibition of oxidation

question

The first detectable sign of vitamin A deficiency is usually

answer

night blindness

question

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

answer

Deficiency of vitamin A

question

Vitamin A supplements are helpful in treating which of the following conditions?

answer

Night blindness

question

The effects of vitamin A deficiency are most severe in what population group?

answer

Newborns

question

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

answer

Xerophthalmia

question

Which of the following is a feature of vitamin A nutrition?

answer

Supplements are recommended for certain groups of infants and children infected with the measles in the United States

question

Keratinization is the result of

answer

deficiency of vitamin A

question

What part of the body is affected most by keratomalacia?

answer

Cornea

question

Keratinization of lung cells may result from

answer

deficiency of vitamin A

question

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

answer

They have chemical structures similar to vitamin A

question

What population group is most vulnerable to vitamin A toxicity?

answer

Children

question

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

answer

They increase teratogenic risk

question

The preferred unit of expression of vitamin A is the

answer

retinol activity equivalent

question

Which of the following is a feature of Accutane?

answer

It is known to cause birth defects when used by pregnant women

question

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

answer

12

question

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

answer

3

question

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

answer

Skin yellowing

question

Why shouldn't a woman who is 7 months pregnant be prescribed Accutane?

answer

It is a teratogen and can be harmful to the baby

question

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

answer

Those taking vitamin A supplements

question

To decrease risk for vitamin A toxicity-related birth defects, it is suggested that pregnant women limit vitamin A supplements to less than

answer

4 times the RDA

question

The adult RDA for vitamin A is approximately

answer

800 retinol activity equivalents

question

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

answer

Consuming high-dose vitamin A supplements

question

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

answer

They are found in many vegetables and fruits

question

Which of the following is a feature of vitamin A in foods?

answer

Chlorophyll in dark green leafy vegetables masks the presence of beta-carotene

question

Your sister Ellen has just joined the Peace Corps and will be working on ways to improve the nutritional status of children in Indonesia. Once there, she saw that many of the children and some adults suffer from night blindness. Which of the following foods should she recommend be incorporated into the Indonesian diet to help prevent future generations from developing this condition?

answer

Sweet potato

question

Which of the following is a characteristic of vitamin A in foods?

answer

A regular intake of chicken liver is known to induce toxicity in children

question

The plant version of vitamin D is known as

answer

ergocalciferol

question

The animal version of vitamin D is known as

answer

cholecalciferol

question

Which of the following organs is NOT required for the complete synthesis of activated vitamin D?

answer

Small intestine

question

Which of the following compounds serves as the major precursor for the body's synthesis of vitamin D?

answer

Cholesterol

question

What percentage of the U.S. population is deficient in vitamin D?

answer

10

question

What percentage of the U.S. population shows marginal or deficient vitamin D status?

answer

35

question

Which of the following can the body use to synthesize vitamin D?

answer

Exposure to sunlight

question

In what tissue(s) must a molecule of vitamin D be chemically altered to yield a compound that is fully active?

answer

Liver and kidney

question

Which of the following compounds is known to function as a hormone?

answer

Vitamin D

question

What is/are the main function(s) of vitamin D?

answer

Promotes calcium and phosphorus absorption and promotes calcium mobilization from bone

question

Where is calbindin primarily found in the body?

answer

Intestine

question

Which of the following is NOT a known risk factor for development of rickets in the United States?

answer

Lacto-ovo vegetarian

question

A child with bowed legs is likely deficient in vitamin

answer

D

question

What is the name of the vitamin D-deficiency disease in adults?

answer

Osteomalacia

question

What population group is at highest risk for osteomalacia?

answer

Adult women

question

In what system would the effects of a vitamin D deficiency be most readily observed?

answer

Skeletal

question

Which of the following symptoms would indicate a vitamin D deficiency?

answer

Bowed legs

question

Which of the following conditions or diseases are known to be caused by a deficiency of the same nutrient?

answer

Osteomalacia and rickets

question

Which of the following is NOT a feature of vitamin D deficiency?

answer

It causes excess iron absorption

question

Which of the following may result from excessive intakes of vitamin D by adults?

answer

Mineral deposits in soft tissues such as the kidney

question

Which of the following is a feature of vitamin D?

answer

The average consumption in the United States does not meet the recommended intake

question

Which of the following is a characteristic of vitamin D nutrition?

answer

Prolonged exposure to sunlight degrades the vitamin D precursor in skin, thus preventing vitamin D toxicity

question

Which of the following enables much of the world's population to maintain adequate vitamin D status?

answer

Outdoor exposure of the skin to sunlight

question

Which of the following conditions is known to lead to formation of mineral deposits in the blood vessels and kidney?

answer

Excessive intake of vitamin D

question

Which of the following is a feature of vitamin D synthesis?

answer

Dark-skinned people require longer sunlight exposure than light-skinned people to synthesize equivalent amounts of vitamin D

question

Which of the following is a naturally occurring food source of vitamin D?

answer

Egg yolks

question

What is the Recommended Dietary Allowance for vitamin D in individuals around 20 years of age?

answer

15 μg

question

Absorption efficiency of vitamin D supplements is markedly improved when they are taken

answer

with a large meal

question

Which of the following vitamins has been noted as preventing the oxidation of low-density lipoproteins?

answer

E

question

The main function of vitamin E in the body is to act as a(n)

answer

antioxidant

question

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

answer

Eliminator

question

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

answer

Both function as antioxidants

question

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

answer

It slows oxidation of low-density lipoproteins

question

The major function of vitamin E is to inhibit the destruction of

answer

polyunsaturated fatty acids

question

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

answer

Alpha

question

Which of the following vitamins is least associated with the process of bone remodeling?

answer

E

question

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

answer

Erythrocyte hemolysis

question

Which of the following is a feature of vitamin E?

answer

Deficiencies occur from inability to absorb dietary lipids

question

Why are primary vitamin E deficiencies rarely observed in human beings?

answer

The vitamin is widespread in foods

question

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

answer

Intermittent claudication

question

To convert the number of tocopherol equivalents to alpha-tocopherol, multiply by the factor

answer

0.8

question

Which of the following is a property of the tocopherols?

answer

Easily destroyed by air and oxygen

question

Which of the following is a feature of vitamin E in foods?

answer

Most convenience foods are poor sources of vitamin E

question

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

answer

65

question

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

answer

E

question

Which of the following is characteristic of the tocopherols?

answer

They are usually found in foods high in polyunsaturated fats

question

Which of the following properties do vitamins D and K share?

answer

Both are synthesized in the body

question

What is prothrombin?

answer

A protein needed for blood clot formation

question

Which of the following is known to require vitamin K for its synthesis?

answer

Prothrombin

question

In what chief capacity does vitamin K function?

answer

Blood clotting

question

What feature is shared by vitamins E and K?

answer

Supplements of either may interfere with anticlotting medications

question

Which of the following is a feature of vitamin K?

answer

It participates in synthesis of bone proteins

question

Which of the following is a feature of osteocalcin?

answer

It requires vitamin K to bind to bone-forming minerals

question

Of the following, which would most readily induce a vitamin K deficiency?

answer

Antibiotic therapy

question

Jennifer has just had a baby. When she brings Thomas home, she regales you with the details of her hospital stay. She mentions that shortly after the birth, Thomas received an intramuscular injection of vitamin K, and she wondered why this was done, as it made him cry. You explained that it

answer

prevented possible bleeding events

question

Which of the following is a characteristic of vitamin K nutrition?

answer

Absorption is inhibited when bile production diminishes

question

Which of the following vitamins is synthesized by intestinal bacteria?

answer

K

question

Which vitamin is routinely given as a single dose to newborns?

answer

Vitamin K

question

Knowing the role of vitamin K in the body, in what organ would you expect to find it in large quantities?

answer

Liver

question

What population group has the highest risk for vitamin K deficiency?

answer

Newborns

question

Which of the following is a major form of vitamin K in foods?

answer

Phylloquinone

question

Approximately what percentage of the body's store of vitamin K is derived from GI tract bacterial synthesis?

answer

50

question

What is the adult AI for vitamin K?

answer

90-120 µg

question

What is a free radical?

answer

A molecule that is unstable and highly reactive because it contains unpaired electrons

question

Which of the following is a characteristic of free radicals?

answer

They arise from normal metabolic reactions

question

Substances that promote oxidation are usually termed

answer

prooxidants

question

Which of the following is a characteristic of vitamin C and vitamin E?

answer

Both protect against LDL oxidation

question

Which of the following is a feature of antioxidants and health?

answer

Beta-carotene supplements have actually been shown to increase the risk of lung cancer in smokers

Chapter 11 – The Fat-Soluble Vitamins A, D, E, and K – Flashcards

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