Which of the following is a feature of vitamins?
The quantities present in foods are measured in micrograms or milligrams
What is meant by the bioavailability of a vitamin in food?
The amount absorbed and subsequently used by the body
General characteristics of the water-soluble vitamins include all of the following EXCEPT
They must be consumed daily
All of the following are general characteristics of the fat-soluble vitamins EXCEPT
excesses are eliminated from the kidneys
Cooking a food in liberal amounts of water is least likely to affect the vitamin content of
When thiamin is consumed in excess of needs, how does the body treat the excess?
Excreted primarily in the urine
Which of the following explains why B vitamin deficiencies lead to lack of energy?
Coenzymes needed for energy metabolism are produced in insufficient amounts
Which of the following describes the basic function of a coenzyme?
Attaches to an enzyme and allows a chemical reaction to take place
Which of the following functions has a requirement for thiamin?
Energy release from energy-yielding nutrients
What is the primary chemical reaction in which thiamin participates as a coenzyme?
Assists in removal of one-carbon units from compounds involved in energy metabolism
Which of the following is a characteristic of thiamin nutrition?
It is an integral part of the nerve cell membrane
All of the following are characteristic of thiamin nutrition EXCEPT
Recommended intakes are stated in "equivalents"
How does the method of cooking affect thiamin stability?
Microwaving the food conserves much of the thiamin
Which of the following vitamins is involved substantially in energy transformation reactions?
Which of the following is indicative of a dietary deficiency of riboflavin?
Inflamed mouth membranes
Which of the following food groups ordinarily contains the highest amount of riboflavin when expressed per kcalorie?
Of the following commonly eaten foods, which makes the greatest contribution to riboflavin intake?
A deficiency of what vitamin produces a characteristic cracking and redness at the corners of the mouth?
Which of the following is a property of niacin in nutrition?
It can be synthesized in the body from the essential amino acid tryptophan
Which of the following properties is shared by niacin and riboflavin coenzymes?
Acceptance and transfer of hydrogen atoms
When the diet contains an adequate amount of protein, what amino acid can be used by the body to synthesize niacin?
Which of the the following nutrients functions to prevent the appearance of a bilateral, symmetrical dermatitis, primarily on the areas exposed to the sun?
A low-protein diet in which corn is a principal food has been found to cause a deficiency of what vitamin?
What vitamin deficiency disease appeared in people who had subsisted on a diet high in corn and low in protein?
A general niacin deficiency is know to be manifested in abnormalities of all of the following organs/systems EXCEPT
While researching your southern family history, you find that your grandmother had a sister who died fairly young. The symptoms leading up to her death included diarrhea, dermatitis, and dementia. Because the family led a poor, corn-farming existence, you suspect this relative died of
Which of the following substances is found in corn and contributes to the development of pellagra?
What term identifies the characteristic tingling sensations and reddening of the skin after ingesting a pharmacologic dose of nicotinic acid?
Which of the following overt side effects is likely to appear after a person ingests a high quantity of nicotinic acid?
Painful, tingling, itching sensation
When taken in large doses, which of the following vitamins is associated with liver injury and peptic ulcers?
Large doses of nicotinic acid are known to result in all of the following EXCEPT
disappearance of learning disorders in children
Your friend Jane just returned from the doctor who diagnosed her with a specific vitamin B toxicity. However, she doesn't recall the name of the vitamin. Which of the following is the only possible culprit associated with toxicity symptoms?
Your brother Bob is a competitive body builder. His trainer suggested that he consumes 4 egg white omelets per day. Bob remembers a warning about a possible vitamin deficiency from consuming too many egg whites and asks if he should follow the prescribed diet. Your reply to Bob is that he should NOT
be concerned, because, when the eggs are cooked, the avidin protein is denatured, and thus does not pose a problem for deficiency disease.
Features of biotin in nutrition include all of the following EXCEPT
a deficiency can be induced by ingesting large amounts of thiamin and folic acid, which interfere with its absorption
Among the following compounds that serve as coenzymes in metabolism, which is considered a vitamin for human beings?
Which of the following foods contains a protein that decreases bioavailability of biotin?
raw egg whites
A protein that binds with biotin (thus inhibiting absorption) is found in which food?
Raw egg whites
Which of the following vitamins is known to sustain substantial losses during processing of food?
Which of the following is NOT a characteristic of vitamin B6 in nutrition?
It is required in amounts proportional to energy expenditure
All of the following are features if vitamin B6 metabolism EXCEPT
It enhances physical performance when supplied at a level of 1 mg/g of dietary protein
A common drug for the treatment of tuberculosis is known to markedly interfere in the metabolism of vitamin
Which of the following statements reflects our knowledge of water-soluble vitamin toxicity?
Toxicity symptoms for vitamin B6 can be severe and irreversible
In what major way does alcohol intake affect vitamin B6 metabolism?
It dislodges the PLP coenzyme from its enzyme
All of the following are properties of folate in nutrition EXCEPT
it functions primarily in the transfer of amino groups
Which of the following characteristics is shared by vitamin B12 and folate?
Both are required for nucleic acid synthesis
Which of the following vitamins is usually found in a form that is bound to one or more glutamic acid molecules in food?
A person with a disorder that limits absorption of bile is at increased risk for deficiency of
What is the most likely explanation for the impaired functioning of the GI tract resulting from folate deficiency?
Since folate functions, in large part, in the process of cell renewal, a deficiency slows mucosal cell replacement, thereby resulting in decreased GI functioning
Which of the following is NOT a feature of folate nutrition?
Folate must be methylated by homocysteine prior to crossing the bush border membrane
Which of the following is a feature if folate nutrition?
Synthetic folate is 70% more available than naturally occurring food folate
By law, what amount of folate (ug) must be added to 100 g of food products such as breads, flour, and rice?
A deficiency of which of the following vitamins results in accumulation of homocysteine in the blood?
The appearance of vitamin B12 deficiency symptoms may be delayed due to high intake of supplements of
What vitamin is involved mainly with the replacement of red blood cells and digestive tract cells
Which of the following substances is known to adversely affect folate utilization?
Regular use of antacids
Which of the following is representative of folate availability in foods?
Much of the vitamin is lost due to heat and oxidation
Which of the following is known to significantly affect the body's folate status?
Some anticancer drugs
Physiological stresses such as blood loss, burns, measles, and cancers are know particularly to increase the risk of deficiency for
What is the function of intrinsic factor in vitamin B12 absorption?
It attaches to the vitamin, thereby allowing absorption from the intestines
All of the following are required for efficient dietary absorption of vitamin B12 EXCEPT
What is the most likely reason for the development of a vitamin B12 deficiency
The absorption of which of the following vitamins is most affected by the disorder atrophic gastritis?
Which of the following is a common treatment for pernicious anemia caused by inadequate absorption?
Injection of cobalamin
If a person refrained from ingesting any of the water-soluble vitamins, deficiency symptoms would appear last for
Normally, the body's storage and re-utilization of vitamin B12 prevents a primary or secondary deficiency from occurring until after about
In a person who loses the ability to absorb vitamin B12, approximately what period of time could elapse before deficiency signs develop?
Pernicious anemia results from a combinations of lack of intrinsic factor and
lack of hydrochloric acid
Which of the following is NOT known to be a risk factor for development of atrophic gastritis?
Avoidance of leafy vegetables
Which of the following is a feature of vitamin B12 bioavailability?
Synthetic B12 in supplement form is highly utilizable
Among the following water-soluble vitamins, a secondary deficiency would most likely be seen for
Why are vegetarians at risk of developing a vitamin B12 deficiency?
Vegetarian diets provide insufficient amounts of the vitamin
Which of the following is a characteristic of vitamin B12?
it is inactivated when the food is heated in a microwave
Which of the following charcterisitics is shared by vitamins B6, B12, C, and folate?
Consumption prevents anemia
Which of the following represents the results of well-controlled studies of vitamin C supplementation on the resistance to, and recovery from colds?
There was a signigicat reduction in the duration of colds in people who consumed at least one gram a day
Why might vitamin C supplements be beneficial in treating the common cold?
The destroy intedtinal pathogens
Which of the following vitamins is known to deactivate histamine, a substance that causes nasal congestion?
What is the minimun daily amount of ascorbic acid that will prevent the apperance of scorbutic symptons in human beings?
Which of the following symptoms is indicative of a deficiency of vitamin C?
Subcutaneous pinpoint hemorrhages
People with the condition known as iron overload may be adversely affected form taking supplements of
What term is used to describe the outcome of a diagnostic test that apparently shows that you have mononucleosis when in reality you do not?
What term describes the outcome of a diagnostic test that apparently indicates that you do not have an infection when in reality you do?
John is looking to increase his dietary sources of vitamin C. However, he expresses a strong dislike for all citrus fruits. Which of the following shopping lists would you recommend?
Brussels sprouts, broccoil, strawberries
Which of the following would be a very good source of vitamin C for the lacto-ovo-vegetarian?
All of the following are consequences of ingesting vitamin C supplements EXCEPT
they enhance the action of anticlotting medications
What food makes a significant contribution to vitamin C intakes in the U.S. population despite the modest vitamin C concentration?
A vitamin supplement labeled as "high potency" contains an amount that is
100% or more of the daily value
The known dangers of taking vitamin supplements include all of the following EXCEPT
pathogenic bacterial overgrowth of the large intestines leading to increased risk of infection
Which of the following statements is representative of vitamin supplementation practices?
People who have low energy intakes or are pregnant are at risk for developing deficiencies and may benefit from supplementation
A person who shuns dairy and spends most of her time indoors would likely benefit from a supplement of
Those groups of people who are at risk for developing marginal nutrient deficiencies and may benefit from taking vitamin supplements include all of the following EXCEPT
Athletes who are engaged in intense competitivie events
Which of the following is NOT among the features of the fat-soluble vitamins?
Transported permanently to the liver and adipose tissue
What is the major carrier of the fat-soluble vitamins from the intestinal epithelial cell to the circulation?
Which of the following is a property f the fat-soluble vitamins?
Deficiency symptoms make 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?
Which of the following is responsible for transporting vitamin A from the liver to other tissues?
As far as is known, vitamin A does not play an important role in which of the following processes?
What are the known effects of raising animals on diets containing retinoic acid as the only source of vitamin A?
Which of the following describes an association of 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?
Which of the following describes an even in the visual response process?
Light energy strikes the retina and excites pigments to release retinal
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.
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 of
Which of the following is most likely to occur from a prolonged dietary deficiency of vitamin A?
Which of the following features are shared by Retin-A and Accutane?
they have chemical structures similar to vitamin A
Which of the following is a feature of taking high-dose supplements of vitamin A?
They increase teratogenic risk
Which of the following is a feature of Accutane?
It is known to cause birth defects when used by pregnant women
All of the following are characteristics of excess consumption of beta-carotene EXCEPT
overconsumption from supplements is harmless
Which of the following is the most likely side effect for a person who regularly consumes large quantities of carrots or carrot juice?
Why shouldn't a 7-month pregnant woman be prescribe Accutane?
it is a teratgen 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 than
4 times the RDA
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 food?
Carotenoid absorption efficiency from salads is higher when regular dressing is used compared with low-fat dressing
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 is a feature of carotenoids in food?
Absorption from the GI tract is blunted by consuming a salad with fat-free dressing
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?
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
All of the following organs are required for the complete synthesis of activated vitamin D EXCEPT the
Which of the following compounds serves as the major precursor for the body's synthesis of vitamin D?
In what tissue(s) must a molecule of vitamin D be chemically altered to yield a compound that is fully active?
liver and kidney
The major target organs for the action of activated vitamin D include all of the following EXCEPT the
What is/are the main functions of vitamin D?
Promotes calcium and phosphorus absorption and promotes calcium mobilization from bone
Which of the following conditions or diseases are known to be caused by a deficiency of the same nutrient?
Osteomalacia and rickets
All of the following are characteristics of vitamin D nutrition EXCEPT
the requirement is increased in most people who are exposed to the sun
Which of the follow is NOT known to promote vitamin D deficiency in the elderly?
Excessive use of hypertension medication
The risk for vitamin D deficiency increase with advancing age for all of the following reasons EXCEPT reduced
absorption of dietary vitamin D
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. Since 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 characteristics 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 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 NOT a feature of vitamin D nutrition?
Excessive exposure to the sun increases risk for vitamin D toxicity
Recently, there has been a lot of news about the importance of antioxidants in the diet. Which of the following vitamins has been noted as preventing the oxidation of low-density lipoproteins?
How is vitamin E thought to play a role in reducing the risk of heart disease?
it slows oxidation of low-density lipoproteins
The process of bone remodeling is known to be dependent on all of the fat-soluble vitamins EXCEPT
Which of the following disorders may result from vitamin E deficiency in people?
Which of the following is a feature of vitamin E?
deficiencies occur from inability to absorb dietary lipids
There is some evidence for benefits from vitamin E supplements in all of the following groups EXCEPT
people with problems of sexual impotence
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?
Which of the following is characteristic of the tocopherols?
They are usually found in foods high in polyunsaturated fats
Which of the following is a feature of vitamin K?
Bacteria in the intestines synthesize bioavailable vitamin K
Which of the following is a feature of osteocalcin?
It requires vitamin K to bind to bone-forming minerals
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 birth, Thomas received an intramuscular injection of vitamin K, and she wondered why this was done, as it made him cry. You explain that it
prevented possible bleeding events
All of the following are features of vitamin K in nutrition EXCEPT
gut microflora synthesis supplies sufficient amounts to meet the needs of most healthy adults
Knowing the role of vitamin K in the body, in what oran would you expect to find it in large quantities?
Which of the following is a feature of vitamin K?
No adverse effects have been reported with high intakes
What type of foods should be controlled in individuals taking anticoagulant medicines?
Green leafy vegetables
Approximately what percentage of the body's store of vitamin K is derived from GI tract bacterial synthesis?
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