Vitamins

Which of the following is correct concerning vitamin B6? a. The body's requirement for B6 is proportional to protein intakes. b. It is not possible to reach toxic levels of B6 since it is a water-soluble vitamin. c. It is effective in aiding sleep disorders. d. It is effective in curing carpal tunnel syndrome.

Vitamin B6 plays so many roles in protein metabolism that the body's requirement for vitamin B6 is roughly proportional to protein intakes. See pages 257-258

All of the following are correct about vitamin E EXCEPT: a. it improves athletic endurance and skill. b. it is widespread in food. c. deficiency can lead to erythrocyte hemolysis in premature infants. d. it is crucial for nerve development

Research in human beings has discredited claims that vitamin E improves athletic endurance and skill, enhances sexual performance, or cures sexual dysfunction in males. See page 239

What is an antioxidant? a. An antioxidant prevents oxygen from binding to hemoglobin. b. An antioxidant is an enzyme needed for the digestion of oxygen. c. An antioxidant prevents damage to cell structures that may be caused by oxidation. d. An antioxidant is required for the digestion of lipids.

While essential to human life, oxygen is capable of inflicting severe damage on cell structures. As discussed on page 234, antioxidants prevent damage to cell structures that may be caused by oxygen-induced oxidation.

Which of these methods of food preparation would maximize the retention of water-soluble vitamins? a. cook foods in oil b. cook foods for long periods of time c. cook foods in water d. cook foods at a high temperature

cook foods in oil. Since, as discussed on page 242, water-soluble vitamins are soluble in water they would be leached out and lost to the cooking water (see Table 7-5 on page 247). However, since water-soluble vitamins are not soluble in lipids, such as oils, little is lost to cooking oil.

Night blindness and xerophthalmia are the early and late stages of a deficiency of which vitamin? a. vitamin A b. niacin c. vitamin B12 d. vitamin D

Vitamin A

Vitamin B6 helps convert tryptophan to niacin in the body. a. True b. False

True. Vitamin B6 aids in the conversion of tryptophan to niacin. See page 257

According to your text, which of the following is NOT a valid reason to take a nutrient supplement? a. "I am a long-term alcoholic who just began a recovery and rehabilitation program." b. "I am a lacto-vegetarian who bleeds heavily during menstrual periods." c. "I am a middle-aged lacto-ovo-vegetarian man." d. "I am a senior citizen, and I eat much less than I used to in order to maintain my weight."

"I am a middle-aged lacto-ovo-vegetarian man." Controversy 7 (pages 269-275) contrasts the situations in which supplementation may be beneficial with those in which supplementation may be harmful. Because they consume a variety of animal and plant foods and don't omit any entire food groups from their diets, otherwise healthy lacto-ovo-vegetarians do not need supplements. Vegans, strict vegetarians who omit all animal foods from the diet, need supplements of vitamin B12, vitamin D (unless they get year-round sun exposure), iron and zinc.

What is the best way for an individual to ensure that they consume adequate amounts of all vitamins without consuming excess calories? a. memorize which foods are the richest source(s) of each vitamin b. take a multivitamin supplement on a daily basis c. practice diet planning principles discussed in Chapter 2 d. exercise

As discussed in Chapter 2 and on pages 264-267, wise diet planning ensures adequate nutrition without excessive caloric intake.

Vitamin D promotes the absorption of what two minerals that are essential to bone health? a. calcium and phosphorus b. magnesium and folate c. zinc and fluoride d. copper and chromium

As discussed on page 235, vitamin D promotes the intestinal absorption of both calcium and phosphorus, two of the minerals essential to bone health.

Which of the following are classified as water-soluble vitamins? a. B, C, D, E b. A, D, E, K c. A, E d. B, C

B &C vitamins Thiamin (B 1) Riboflavin (B 2) Niacin (B 3) Folate Vitamin B 12 Vitamin B 6 Biotin Pantothenic acid Vitamin C

Which of these is a water-soluble vitamin? a. vitamin C b. vitamin D c. vitamin A d. vitamin E

C. As seen in Table 7-1 (page 227), vitamins A, D, E, and K are the fat-soluble vitamins. In contrast to water-soluble vitamins, fat-soluble vitamins are absorbed into the lymph, are transported in the blood by carrier proteins, are stored in the liver or fatty tissues, are not readily excreted from the body, and are needed in periodic doses.

Neural tube defects are believed to be related to a woman's niacin intake before and during pregnancy. a. True b. False

False. By consuming enough folate during pregnancy, a woman can reduce her child's risk of having the devastating birth defects known as neural tube defects. See page 254

Most of the symptoms of rickets can be attributed to the breakdown of collagen in the absence of vitamin C. a. True b. False

False. Most of the symptoms of rickets can be attributed to the failure of bones to properly mineralize in the absence of vitamin D. See page 236

Which of the following foods are the best sources of vitamin C and folate? a. meats and vegetables b. dairy and meats c. oil and vegetables d. fruits and vegetables

Fruits and vegetables are the foods to remember for vitamin C and folate. In fact, folate's name is derived from the word foliage because it is abundant in leafy green vegetables. See pages 247, 255

Why does an individual need to make sure that they consume water-soluble vitamins more often than fat-soluble vitamins? a. In general, the body can call upon its stores of fat-soluble vitamins; whereas, most water-soluble vitamins are not stored. b. In general, it is more difficult to absorb water-soluble vitamins; thus, consuming more of these vitamins ensures absorption of the amounts needed for health. c. In general, water-soluble vitamins are more important to health than are fat-soluble vitamins. d. In general, water-soluble vitamins are stored in larger quantities than fat-soluble vitamins.

In general, the body can call upon its stores of fat-soluble vitamins; whereas, most water-soluble vitamins are not stored. As discussed on pages 227-228 and seen in Table 7-2 (page 228), fat-soluble vitamins tend to be stored in the liver and fatty tissues, whereas water-soluble vitamins tend not to be stored and are readily excreted in the urine. For these reasons, it is more important for a person to consume water-soluble vitamins on a daily basis than it is to consume fat-soluble vitamins on a daily basis.

When keratinization occurs in the lungs, what usually occurs? a. Decreased risk of sinus infections. b. No symptoms occur; this is a normal process. c. Increased ability to use oxygen efficiently. d. Increased risk of respiratory infections.

Increased risk of respiratory infections. Keratinization of the lungs makes the tissue surface dry, hard, and cracked, and the respiratory system becomes vulnerable to infection. See page 230

Which of the vitamins are mismatched with their alternate names? a. niacin - B3 b. vitamin A - retinol c. vitamin B6 - riboflavin d. vitamin B1 - thiamin

Niacin is the alternate name for B3. See page 262

Pantothenic acid is a B vitamin that serves as a coenzyme in the metabolism of energy nutrients. What does this mean? a. Pantothenic acid is part of a small molecule that combines with a large protein to catalyze energy-releasing reactions. b. Pantothenic acid signals body cells to break down nutrients for energy when the body needs it. c. Pantothenic acid attacks and breaks the bonds in carbohydrate, fat and amino acid molecules. d. Pantothenic acid acts as an emulsifier in the digestive tract.

Pantothenic acid is part of a small molecule that combines with a large protein to catalyze energy-releasing reactions. Vitamins themselves do not serve as enzymes; this is a major function of protein in the body. However, as explained on page 248 a coenzyme promotes enzyme function. Pantothenic acid (page 259) plays a role in the release of energy from energy-yielding nutrients.

All of the following individuals should consider taking a self-chosen multi-nutrient supplement EXCEPT: a. elderly people. b. people with kidney or liver disease. c. people recovering from surgery, burns, or injury. d. strict vegetarians.

People with kidney or liver disease should never take supplements without a physician's approval because they are susceptible to toxicities. See page 269

________ who take beta-carotene supplements increase their risk of lung cancer. a. Fast food addicts b. "Couch potatoes" c. Athletes d. Smokers

Smokers. Beta-carotene, a vitamin A precursor, acts as an antioxidant. However, as indicated on page 273, smokers who take daily doses of beta-carotene are at an increased risk for lung cancer.

Pernicious anemia is caused by a deficiency of: a. vitamin B12. b. vitamin K. c. vitamin D. d. retinol.

The anemia of the vitamin B12 deficiency caused by a lack of intrinsic factor is known as pernicious anemia. See page 256

Which of the following is NOT a good source of beta-carotene? a. French fries b. mango c. sweet potato d. spinach

The definitive fast-food meal, a hamburger, fries, and cola, lacks vitamin A. See pages 233, 235

Dietary supplements do not require government approval before entering the market, and manufacturers alone decide whether their products are safe and effective. a. True b. False

True

Groups of people with high fruit and vegetable intakes often have low rates of cancer. a. True b. False

True. Groups of people with high fruit and vegetable intakes often have low rates of cancer, particularly for cancers of the mouth, throat, lung, stomach, colon and rectum. See page 273

Vitamin C supplements may enhance iron absorption, making iron overload likely in some people. a. True b. False

True. Since vitamin C enhances iron absorption, supplementation of vitamin C may make iron overload likely in some people. See page 245

The antioxidant vitamins are: a. retinol, vitamin D, and biotin. b. vitamin E, vitamin C, and beta-carotene. c. vitamin C, riboflavin, and folate. d. vitamin D, thiamin, and riboflavin.

Vitamins E, C, and beta-carotene are antioxidant vitamins, compounds typically found in plant foods that significantly decrease the adverse effects of oxidation of living tissues. See page 234

When healthy men are given supplements of ________ their homocysteine values drop significantly. a. vitamin B12, folate, and vitamin B6 b. vitamin K c. vitamin C, vitamin A, and vitamin D d. vitamin A, beta-carotene, and retinol

When healthy men with elevated homocysteine are given supplements of folate, vitamin B6, and vitamin B12, their homocysteine values drop significantly. See page 258

Which of these might be a consequence of vitamin C supplementation? a. a decreased risk of dementia b. an increased risk of oxidative damage c. a decreased risk of diabetes d. an increased risk of an HIV infection

an increased risk of oxidative damage. There is no evidence to suggest that otherwise healthy people who consume adequate diets obtain any benefit from vitamin C supplementation. As discussed on pages 264-265, high doses of vitamin C may correlate with an increase in markers of oxidation in the blood. In addition, high doses of vitamin C increase the risk of death from cardiovascular disease when taken by women who are diabetic.

In general, which food group(s) provides foods that are rich in vitamin C? a. milk, yogurt, and cheese group, and oils group b. grains group and meat, poultry, fish, dried peas and beans, eggs, and nuts group c. solid fats and added sugars group d. fruits group and vegetables group

both the fruits group and the vegetables group provide vitamin C.

Which of the following foods has the highest amount of vitamin C? a. whole-wheat bread b. yogurt c. cantaloupe d. sirloin steak

cantaloupe. Fruits and vegetables, and not just citrus fruits, are excellent sources of vitamin C. See pages 246-247

The best-known role of vitamin D is to: a. act as an antioxidant. b. help synthesize proteins that help clot the blood. c. help maintain blood calcium and phosphorus levels. d. release energy from the energy nutrients.

help maintain blood calcium and phosphorus levels. Vitamin D is the best-known member of a large cast of nutrients and hormones that interact to regulate blood calcium and phosphorus levels, and thereby maintain bone integrity. See page 235

Absorption of vitamin B12 requires: a. iron. b. extrinsic factor. c. intrinsic factor. d. niacin.

intrinsic factor, a compound made by the stomach,

All of the following types of drugs can interfere with the body's use of folate EXCEPT: a. aspirin. b. intrinsic factor. c. oral contraceptives. d. antacids.

intrinsic factor.

All of the following are correct about beriberi EXCEPT: a. it was first observed in East Asia where polished rice was a staple food. b. it is characterized by loss of sensation in the hands and feet, muscular weakness, and paralysis. c. it is due to a niacin deficiency. d. in alcoholics, it is known as Wernicke-Korsakoff syndrome.

it is due to a niacin deficiency.

Which of these methods of food storage would maximize the retention of the vitamins in a food item? a. leave out on a kitchen counter b. store the food in an oven c. refrigerate d. leave on top of a refrigerator

refrigerate. As discussed on page 227, vitamins are organic compounds and thus tend to break down if they are not kept at cool temperatures such as those found in refrigerators. See Table 7-5 on page 247 for more tips for preserving vitamins when preparing or storing foods.

Good food sources of vitamin B12 include: a. dark green vegetables, corn, and cabbage. b. sirloin steak, cottage cheese, and tuna. c. citrus fruits, dairy products, and zucchini. d. potatoes, broccoli, and whole-wheat bread.

sirloin steak, cottage cheese, and tuna. Vitamin B12 is present only in foods of animal origin. See pages 256, 257

How does soft drink consumption contribute to poor bone health? a. the consumption of soft drinks often displaces the sugars required for calcium absorption b. the consumption of soft drinks promotes the excretion of fluoride c. the consumption of soft drinks kills the intestinal bacteria that produce vitamin K d. the consumption of soft drinks often displaces vitamin D-fortified milk in the diet

the consumption of soft drinks often displaces vitamin D-fortified milk in the diet. Unless it is diet soft drinks that are being consumed, soft drinks are high in sugar. As discussed on page 236, teenagers may choose to consume soft drinks rather than vitamin D-fortified milk. Vitamin D (page 235), unlike added sugars, is required for the absorption of calcium and phosphorus, two minerals essential to bone health. Vitamin D also plays a role in the regulation of calcium balance within the body

Fat-soluble vitamins are absorbed into ________; water-soluble vitamins are absorbed into ________. a. the lymph; capillaries b. capillaries; capillaries c. capillaries; the lymph d. the lymph; the lymph

the lymph; capillaries. As discussed on pages 227-228 and seen in Table 7-2 (page 228), fat-soluble vitamins, like other fat-soluble nutrients, are absorbed into the lymph and then are transported in the blood bound to transport proteins. In contrast, like other water-soluble nutrients, water-soluble vitamins are absorbed directly into the watery medium (blood) contained within capillaries.

All of the following are characteristics of the fat-soluble vitamins EXCEPT: a. they may be toxic in excess. b. they require bile for absorption. c. they dissolve in lipids. d. they are easily absorbed and excreted in urine.

they are easily absorbed and excreted in urine. Water-soluble vitamins are readily excreted in the urine, while fat-soluble vitamins are not readily excreted because they tend to build up in the tissues. See page 228

Which vitamin supplement has caused malformations of a fetus? a. vitamin C b. thiamin c. vitamin B12 d. vitamin A

vitamin A

Which vitamin is mismatched with its deficiency? a. vitamin D - pernicious anemia b. vitamin C - scurvy c. thiamin - beriberi d. niacin - pellagra

vitamin D - pernicious anemia, Vitamin D deficiency is manifested as rickets, while vitamin B12 deficiency is pernicious anemia. See page 236

Which of the following is NOT a possible toxicity symptom associated with vitamin C excesses? a. nausea b. yellowing of the skin c. rashes d. diarrhea

yellowing of the skin

Which of these methods of food preparation would MAXIMIZE vitamin loss via food preparation? a. steam b. boil c. cut and consume raw d. microwave for a short period of time

•Cook fruits and vegetables in a microwave oven, or quickly stir fry, or steam them over a small amount of water to preserve heat-sensitive vitamins and to prevent vitamin loss in cooking water. Recapture dissolved vitamins by using cooking water for soups, stews, or gravies. •Avoid high temperatures and long cooking times.

Which of these is a key antioxidant vitamin? a. niacin b. folate c. vitamin E d. pantothenic acid

As discussed on page 239, vitamin E is an antioxidant. Vitamin E, and the other key antioxidant vitamins (beta-carotene and vitamin C) and the important antioxidant mineral, selenium, are listed on page 234.

Which vitamin may be deficient in people who rely solely on fat replacers and fat-free foods to the exclusion of real fat? a. C b. D c. B12 d. E

E. People who rely solely on fat replacers and fat-free foods to the exclusion of real fat may be deficient in vitamin E because it dissolves in lipids and is found in many plant oils. See pages 239-240

Which of the following vitamins' main role is to help synthesize proteins that help blood clot? a. beta-carotene b. E c. D d. K

The main function of vitamin K is to help synthesize proteins that help clot the blood. See page 241

Which of these methods of food preparation would maximize the retention of fat-soluble vitamins? a. cook foods in oil b. cook foods for long periods of time c. cook foods in water d. cook foods at a high temperature

cook foods in water. Since, as discussed on page 227, fat-soluble vitamins are soluble in oil little would be leached out and lost if the food was cooked in water. However, since fat-soluble vitamins are soluble in lipids, such as oils, there would be considerable loss to cooking oil (see Table 7-5 on page 247).

Which of these is a fat-soluble vitamin? a. riboflavin b. folate c. niacin d. vitamin K

K. As seen in Table 7-1 (page 227), the water-soluble vitamins are vitamin C and the B vitamins (thiamin, riboflavin, niacin, folate, vitamin B12, vitamin B6, biotin, and pantothenic acid). Unlike the fat-soluble vitamins, water-soluble vitamins are absorbed into the blood, travel freely in the watery fluids of the body, are not stored and therefore needed in frequent doses, and are readily excreted in the urine.

Which of the following adults is most likely to suffer from osteomalacia? a. lacto-ovo-vegetarian b. an individual who consumes fruits, vegetables, grains, eggs, cheese, and fish only c. vegan d. an individual who consumes a variety of foods from each of the food groups in the USDA Food Guide

VEGAN. As discussed on page 236, a lack of vitamin D may cause osteomalacia, a condition in which bone is suffering from inadequate mineralization. Reviewing the USDA Food Guide you will see that both calcium and vitamin D are primarily found in foods of animal origin and that, unless they carefully plan their diet, a vegan is at a great risk of not consuming sufficient amounts of these nutrients.

________ are both participants in the release of energy from macronutrients, while ________ are both participants in cell multiplication. a. Pantothenic acid and thiamin; niacin and vitamin B12 b. Riboflavin and vitamin B12; folate and thiamin c. Folate and riboflavin; niacin and thiamin d. Thiamin and niacin; vitamin B12 and folate

A review of Table 7-7 (pages 262-264) will provide you with a summary of the functions of the B vitamins. Vitamin B12's coenzyme form is involved in synthesis of new cells, and this vitamin is also necessary for the maintenance of nerve cells. Thiamin's major role is as part of a coenzyme in energy metabolism. The active forms of thiamin, riboflavin, niacin, pantothenic acid, and biotin serve as "helpers" in the release of energy from carbohydrate, protein and fat. Folate and vitamin B12 assist cells to multiply and replace the cells with short life spans, such as red blood cells and cells lining the digestive tract.

Which of these might be a consequence of vitamin A supplementation? a. increased blood calcium level b. liver damage, muscle weakness, and an over-reactive immune system c. excessive blood clotting d. Vitamin A is relatively non-toxic, so there are no potential adverse consequences from the consumption of vitamin A supplements.

As discussed on page 231 and listed in Tables 7-4 (page 232) and 7-6 (page 260), liver damage, muscle weakness, and an over-reactive immune system are all potential consequences of consuming high doses of vitamin A.

Which of these is a key antioxidant vitamin? a. vitamin K b. vitamin D c. vitamin C d. vitamin A

As discussed on page 244, vitamin C is an antioxidant. Vitamin C, and the other key antioxidant phytochemicals (beta-carotene), vitamins (vitamin E), and the important antioxidant mineral, selenium, are listed on page 234.

Which of the food groups provides the richest sources of vitamin E? a. oils group b. fruits group c. vegetables group d. milk, yogurt, and cheese group

Vitamin E is a fat-soluble vitamin and as such the oils group provides foods that are the richest in this vitamin (pages 240-241).