ch 11 MC

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

Chylomicrons

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

c.Deficiency symptoms may take years to develop on a poor diet

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

Intestinal cells

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

Beta—carotene

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

three

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

Retinol-binding protein

With what vitamin is opsin usually associated in the body?

A

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

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

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

Retinal

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

a.Light energy strikes the retina and excites pigments to release retinal.

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

90

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

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

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?

1 to 2 years

Worldwide, how many preschool age children go blind each year due to vitamin A deficiency?

500,000

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

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

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

b.vitamin A.

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

d.Night blindness

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

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

Which of the following is a feature of Accutane?

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

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

Skin yellowing

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

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

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

pumpkin pie

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

Arctic explorers who have eaten large quantities of polar bear liver have become ill with symptoms suggesting vitamin A toxicity.

The plant version of vitamin D is known as

ergocalciferol.

The animal version of vitamin D is known as

cholecalciferol.

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

Cholesterol

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

10

The main function of vitamin D is to promote

calcium and phosphorus absorption, and calcium mobilization from bone.

Where is calbindin primarily found in the body?

Intestine

A child with bowed legs is likely deficient in vitamin

D

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

Osteomalacia

What population group is at highest risk for osteomalacia?

Adult women

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

Mineral deposits in soft tissues such as the kidney

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?

Vitamin D-fortified milk

Which of the following is a feature of vitamin D?

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

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

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

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

Outdoor exposure of the skin to sunlight

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

Excessive intake of vitamin D

Which of the following is a feature of vitamin D?

Fortification of milk with the vitamin is common in order to provide people with a reliable source.

Which of the following is the most reliable source of vitamin D in the diet?

Fortified milk

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

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

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

egg yolks

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

15 μg

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

with a large meal

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

E

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

antioxidant

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

It slows oxidation of low-density lipoproteins.

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

polyunsaturated fatty acids.

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

Alpha

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

Erythrocyte hemolysis

Which of the following is a feature of vitamin E?

Deficiencies occur from inability to absorb dietary lipids.

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

Intermittent claudication

Which of the following is a property of the tocopherols?

Easily destroyed by air and oxygen

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

Most convenience foods are poor sources of vitamin E.

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

Vegetable oils

Which of the following is characteristic of the tocopherols?

They are usually found in foods high in polyunsaturated fats.

What is prothrombin?

A protein needed for blood clot formation

In what chief capacity does vitamin K function?

Blood clotting

Which of the following is a feature of vitamin K?

Vitamin K participates in synthesis of bone proteins.

Which of the following is a feature of osteocalcin?

It requires vitamin K to bind to bone-forming minerals.

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

Antibiotic therapy

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

Absorption is inhibited when bile production diminishes.

Which of the following vitamins is synthesized by intestinal bacteria?

K

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

Vitamin K

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

newborns

Which of the following is a feature of vitamin K?

No adverse effects have been reported with high intakes.

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

Phylloquinone

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

50

Which of the following is a characteristic of free radicals?

They arise from normal metabolic reactions.

Substances that promote oxidation are usually termed

prooxidants.