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

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?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?3
Which of the following is responsible for transporting vitamin A from the liver to other tissues?Retinol-binding protein
As far as is known, vitamin A does not play an important role in which of the following processes?Blood clotting
Retinol-binding protein is required to transport vitaminA
What form of vitamin A supports reproduction but not growth?Retinol
What form of vitamin A supports vision but not growth?Retinal
What do retinal and unsaturated fatty acids have in common?They may exist in the cis or trans form
With what vitamin is opsin usually associated in the body?A
What are the known effects of raising animals on diets containing retinoic acid as the only source of vitamin A?Blindness develops
Which of the following describes an association between vitamin A and vision?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?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
What tissue contains the majority of the body’s store of vitamin A?Liver
Which of the following describes the primary function of vitamin A in bone health?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
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?“Don’t worry; fat-soluble vitamins are stored in the body. It takes a lot longer than one day to develop any adverse effects.”
Which of the following vitamins is most associated with promoting synthesis of gastrointestinal mucus?A
What do beta-carotene and vitamin E have in common?Both act as antioxidants
Approximately how many children worldwide have vitamin A deficiency?250 million
Why does vitamin A status depend on the person’s protein status?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 ofvitamin A
Which of the following functions is shared by beta-carotene and vitamin E?Inhibition of oxidation
The first detectable sign of vitamin A deficiency is usuallynight blindness
Which of the following is associated with the condition known as xerosis?Deficiency of vitamin A
Vitamin A supplements are helpful in treating which of the following conditions?Night blindness
The effects of vitamin A deficiency are most severe in what population group?Newborns
Which of the following is most likely to occur from a prolonged dietary deficiency of vitamin A?Xerophthalmia
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
Keratinization is the result ofdeficiency of vitamin A
What part of the body is affected most by keratomalacia?Cornea
Keratinization of lung cells may result fromdeficiency of vitamin A
Which of the following features are shared by Retin-A and Accutane?They have chemical structures similar to vitamin A
What population group is most vulnerable to vitamin A toxicity?Children
Which of the following is a feature of taking high-dose supplements of vitamin A?They increase teratogenic risk
The preferred unit of expression of vitamin A is theretinol activity equivalent
Which of the following is a feature of Accutane?It is known to cause birth defects when used by pregnant women
How many micrograms of dietary beta-carotene are equivalent to 1 retinol activity equivalent?12
On average, one retinol activity equivalent is equal to about how many international units?3
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
Why shouldn’t a woman who is 7 months pregnant be prescribed Accutane?It is a teratogen and can be harmful to the baby
In which of the following individuals would vitamin A toxicity be most likely to occur?Those taking vitamin A supplements
To decrease risk for vitamin A toxicity-related birth defects, it is suggested that pregnant women limit vitamin A supplements to less than4 times the RDA
The adult RDA for vitamin A is approximately800 retinol activity equivalents
Which of the following is likely to induce vitamin A toxicity in adults?Consuming high-dose vitamin A supplements
Which of the following is a characteristic of carotenoids in foods?They are found in many vegetables and fruits
Which of the following is a feature of vitamin A in foods?Chlorophyll in dark green leafy vegetables masks the presence of beta-carotene
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?Sweet potato
Which of the following is a characteristic of vitamin A in foods?A regular intake of chicken liver is known to induce toxicity in children
The plant version of vitamin D is known asergocalciferol
The animal version of vitamin D is known ascholecalciferol
Which of the following organs is NOT required for the complete synthesis of activated vitamin D?Small intestine
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
What percentage of the U.S. population shows marginal or deficient vitamin D status?35
Which of the following can the body use to synthesize vitamin D?Exposure to sunlight
In what tissue(s) must a molecule of vitamin D be chemically altered to yield a compound that is fully active?Liver and kidney
Which of the following compounds is known to function as a hormone?Vitamin D
What is/are the main function(s) of vitamin D?Promotes calcium and phosphorus absorption and promotes calcium mobilization from bone
Where is calbindin primarily found in the body?Intestine
Which of the following is NOT a known risk factor for development of rickets in the United States?Lacto-ovo vegetarian
A child with bowed legs is likely deficient in vitaminD
What is the name of the vitamin D-deficiency disease in adults?Osteomalacia
What population group is at highest risk for osteomalacia?Adult women
In what system would the effects of a vitamin D deficiency be most readily observed?Skeletal
Which of the following symptoms would indicate a vitamin D deficiency?Bowed legs
Which of the following conditions or diseases are known to be caused by a deficiency of the same nutrient?Osteomalacia and rickets
Which of the following is NOT a feature of vitamin D deficiency?It causes excess iron absorption
Which of the following may result from excessive intakes of vitamin D by adults?Mineral deposits in soft tissues such as the kidney
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 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 takenwith 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
What is the role of vitamin E in the metabolism of free radicals?Eliminator
Which of the following features do vitamins C and E share?Both function as antioxidants
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 ofpolyunsaturated fatty acids
What form of tocopherol shows vitamin E activity in the human body?Alpha
Which of the following vitamins is least associated with the process of bone remodeling?E
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
Why are primary vitamin E deficiencies rarely observed in human beings?The vitamin is widespread in foods
Which of the following conditions may improve with vitamin E therapy?Intermittent claudication
To convert the number of tocopherol equivalents to alpha-tocopherol, multiply by the factor0.8
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
In comparison with the RDA for vitamin E, about how many fold higher is the Tolerable Upper Intake Level?65
Increasing the amount of polyunsaturated fats in the diet increases the need for vitaminE
Which of the following is characteristic of the tocopherols?They are usually found in foods high in polyunsaturated fats
Which of the following properties do vitamins D and K share?Both are synthesized in the body
What is prothrombin?A protein needed for blood clot formation
Which of the following is known to require vitamin K for its synthesis?Prothrombin
In what chief capacity does vitamin K function?Blood clotting
What feature is shared by vitamins E and K?Supplements of either may interfere with anticlotting medications
Which of the following is a feature of vitamin K?It 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
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 itprevented possible bleeding events
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
Knowing the role of vitamin K in the body, in what organ would you expect to find it in large quantities?Liver
What population group has the highest risk for vitamin K deficiency?Newborns
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
What is the adult AI for vitamin K?90-120 µg
What is a free radical?A molecule that is unstable and highly reactive because it contains unpaired electrons
Which of the following is a characteristic of free radicals?They arise from normal metabolic reactions
Substances that promote oxidation are usually termedprooxidants
Which of the following is a characteristic of vitamin C and vitamin E?Both protect against LDL oxidation
Which of the following is a feature of antioxidants and health?Beta-carotene supplements have actually been shown to increase the risk of lung cancer in smokers