Chapter 5 Vitamins

It is recommended that people older than the age of 50 years take vitamin supplements, but it is important they take the proper type of supplement—namely, "50+" or "mature" multivitamin supplement formulas—because they usually contain what? A) Less iron B) More zinc C) Less vitamin B12 D) More calcium

Ans: A Feedback: "Mature" or "50+" formulas usually have less iron and vitamin K. While seniors do need less iron, the need for vitamin K does not decrease with aging.

There are many enzymes in our body that cannot function without a coenzyme. Which vitamins act as coenzymes? A) B vitamins B) Vitamin C C) Vitamin D D) Vitamin K

Ans: A Feedback: All B vitamins work as coenzymes to facilitate thousands of chemical conversions.

B vitamins are known to be coenzymes and assist with various bodily reactions and functions. Not all coenzymes, however, are considered B vitamins. What substance is a coenzyme and is considered a non-B vitamin? A) Choline B) Isoniazid C) Beta-carotene D) Niacin

Ans: A Feedback: Choline plays important roles in the metabolism and functioning of cells. Although its essentiality is currently uncertain, it may eventually be classified as a B vitamin.

Smoking interferes with the body's use of a specific vitamin, so the RDA for this vitamin has been raised for smokers. Which vitamin is it? A) Vitamin C B) Folate C) Beta-carotene D) Vitamin E

Ans: A Feedback: Cigarette smokers are advised to increase their intake by 35 mg/day because smoking increases oxidative stress and metabolic turnover of vitamin C.

It is recognized that many individuals in the United States do not eat properly; however, it is not always necessary for people to take a vitamin supplement. Who of the following individuals is least likely to need a vitamin supplement? A) A moderately active adult B) A pregnant teenager C) An elderly woman living alone D) A housewife on a low-calorie diet

Ans: A Feedback: It is recommended that certain populations take supplements to ensure they are getting adequate nutrition to prevent deficiencies. These include women who are pregnant, dieters who consume fewer than 1200 calories, vegans, finicky eaters, and a large portion of adults age 51 years and older.

The nurse is conducting an assessment of a new client who has been using megadoses of nutritional supplements for several years. The nurse is aware that consistently high doses of many vitamins have no adverse effects; however, long-term exposure to synthetic folic acid may do which of the following? A) Mask a deficiency of vitamin B12 B) Can cause a temporary sensory neuropathy C) May increase the risk of heart disease D) Increase the need for other B vitamins

Ans: A Feedback: Long-term exposure to synthetic folic acid may mask vitamin B12 deficiency, which can cause permanent neurologic damage if left untreated. Other potential risks include an increased risk of cognitive decline in older people with a low vitamin B12 status, increased tumorigenesis in clients with pre-existing lesions, and increased risk of cancer in general.

The nurse is aware that vitamins have been found to have other functions than to just nourish the body. Vitamins are often used as food additives for specific purposes. Which vitamin is added to frozen fish to help prevent rancidity? A) Vitamin C B) Vitamin E C) Vitamin A D) Vitamin B12

Ans: A Feedback: Some vitamins are used as food additives in certain foods to boost their nutritional content, such as vitamin C and vitamin D. Other foods have certain vitamins added to help preserve quality, such as vitamin C added to frozen fish to help prevent rancidity and to luncheon meats to stabilize the red color. Vitamin E helps retard rancidity to vegetable oils, and beta-carotene adds color to margarine.

It has been proven that folate, when consumed in an adequate amount, may help prevent neural tube defects. When is it necessary to consume the folate to have this effect? A) Before conception and early in pregnancy B) During the second trimester of pregnancy C) During the third trimester of pregnancy D) Throughout pregnancy

Ans: A Feedback: Studies show that an adequate intake of folate before conception and during the first trimester of pregnancy reduces the risk of neural tube defects in infants.

The physician has recommended that a client take a vitamin supplement. What would the client look for when choosing a vitamin supplement? A) The "Supplement Facts" label B) Look for the nutrient's Recommended Dietary Allowance (RDA) C) Choose the highest price supplement D) Choose a supplement that is "natural"

Ans: A Feedback: The FDA requires a standardized "Supplemental Facts" label on all supplements. This label is intended to provide consumers with better information.

A client is concerned she is not getting enough vitamin D in her diet. The nurse explains how we obtain vitamin D and explains that synthesis can be impaired by all of the following, except for? A) Low calcium intake B) Sunscreens C) Aging D) Dense clouds

Ans: A Feedback: The primary function of vitamin D is to maintain normal blood concentrations of calcium and phosphorus. The body has the potential to produce all the vitamin D it needs if exposure to sunlight is optimal and liver and kidney functions are normal.

The nurse is teaching a nutrition class to a group of pregnant women in the community. What should the nurse recommend to the students as a good source of vitamin B12? A) Milk B) Green leafy vegetables C) Vegetable oils D) Peanut butter

Ans: A Feedback: Vitamin B12 holds the distinction of being the only water-soluble vitamin that does not occur naturally in plants. It is found in animal products.

The nurse is aware that particular populations are prone to vitamin deficiencies for various reasons. Why are older adults prone to vitamin D deficiency? A) Aging reduces the kidneys' ability to activate vitamin D. B) They are more likely to take prescription medicines that interfere with vitamin D absorption. C) Their fixed incomes limit buying enough foods rich in vitamin D. D) They excrete more vitamin D than younger adults do.

Ans: A Feedback: Vitamin D is unique in that the body has the potential to make all it needs if exposure to sunlight is optimal and liver and kidney functions are normal. Elderly persons are particularly at risk for vitamin D deficiency if they have impaired activation by the liver and kidneys.

A client is being admitted to the hospital unit with vague complaints. During the assessment, the nurse discovers that the client has been taking supplements in manner in which the vitamins could result in acting more as drugs. When do vitamins act as drugs in the body? A) When they are prescribed by a physician B) When they are taken in megadoses C) When they are taken in combination with other vitamins D) When they are taken in minidoses

Ans: B Feedback: In megadoses (amounts at least 10 times greater than RDA), vitamins function like drugs, not nutrients.

Riboflavin is said to be unique among the water-soluble vitamins. What makes riboflavin unique? A) Meats and beans contribute the most riboflavin to the diet. B) Milk and dairy products contribute the most riboflavin to the diet. C) Meats and beans contribute the least riboflavin to the diet. D) Milk and dairy products contribute the least riboflavin to the diet.

Ans: B Feedback: Riboflavin is unique among water-soluble vitamins in that milk and dairy products contribute the most riboflavin to the diet.

Clients who need to be on antibiotics for a prolonged period of time may be at an increased risk of vitamin K deficiency. Why is this? A) Antibiotics impair vitamin K absorption from foods. B) Antibiotics kill intestinal bacteria that produce vitamin K. C) Antibiotics cause loss of appetite, which lowers vitamin K intake. D) Antibiotics inactivate vitamin K in the liver.

Ans: B Feedback: Vitamin K occurs naturally in two forms: One is found in plants, and the other is synthesized in the intestinal tract by bacteria. These intestinal tract bacteria can be killed by the antibiotics, resulting in a shortage or deficiency of vitamin K.

Vitamins can be either fat soluble or water soluble. Their solubility determines many of their characteristics. What is one characteristic that is determined by a vitamin's solubility? A) Availability B) Storage C) Strength D) Function

Ans: B Feedback: Vitamins are classified according to their solubility. Fat-soluble vitamins are vitamins A, D, E, and K. Water-soluble vitamins are vitamin C and the B vitamins. Solubility determines vitamin absorption, transportation, storage, and excretion.

The health-care provider has instructed the client to eat foods that will provide more vitamin E. Which of the following should the nurse recommend that the client eat? A) Fortified milk B) Egg yolks C) Vegetable oils D) Red meat

Ans: C Feedback: Vitamin E is found in vegetable oils and products made from oil such as margarine, salad dressing, and other prepared foods.

When conducting an assessment on a new client, the nurse asks if the client uses any supplements. The nurse is aware that taking supplements is a common choice that Americans make. What is the approximate percentage of American adults who take vitamin supplements based on their beliefs about health? A) 30% B) 40% C) 50% D) 60%

Ans: C Feedback: An estimated 54% of American adults use dietary supplements, primarily in the form of multivitamins with or without minerals.

The nurse works with several clients who routinely take nutritional supplements. The nurse is aware that which of the following statements about vitamins is true? A) Most Americans do not consume adequate amounts of thiamin, riboflavin, and niacin. B) Most Americans do not consume adequate amounts of vitamin C. C) Taking large doses of vitamin A is potentially harmful. D) Because of the potential health benefits, beta-carotene supplements are routinely recommended.

Ans: C Feedback: Extremely high doses of vitamin A (at least 30,000 μg/day) consumed over months or years may cause central nervous system changes, bone and skin changes, and liver abnormalities that range from reversible to fatal. In high doses during pregnancy, vitamin A is also teratogenic, so supplementation is not recommended during the first trimester unless there is specific evidence of vitamin A deficiency.

The health-care provider has suggested that the client use a particular vitamin in megadoses to help lower serum cholesterol. Which vitamin is it? A) Thiamin B) Riboflavin C) Niacin D) Folic acid

Ans: C Feedback: Large doses of niacin in the form of nicotinic acid (1-6 g/day) are used therapeutically to lower total cholesterol and LDL cholesterol and raise HDL cholesterol.

The body has several defense systems to protect itself. Which vitamins work together to inactivate bacteria and viruses? A) Water-soluble vitamins B) B vitamins C) Phytochemicals D) Fat-soluble vitamins

Ans: C Feedback: Phytochemicals are a broad class of nonnutritive compounds that plants produce to protect themselves against viruses, bacteria, and fungi. In foods, phytochemicals help deactivate bacteria and viruses.

The nurse recognizes that there are differences between fat-soluble and water-soluble vitamins. Which of the following is one of those differences? A) Water-soluble vitamins are more essential to life than fat-soluble vitamins. B) Water-soluble vitamins attach to protein carriers to be transported through the blood. C) Water-soluble vitamins should be consumed daily. D) Water-soluble vitamins are stored primarily in the liver and adipose tissue.

Ans: C Feedback: There are differences between fat-soluble and water-soluble vitamins. Water-soluble vitamins should be consumed daily. The other choices are true about fat-soluble vitamins.

Vitamin deficiency in the United States is not common. However, inadequate gastric acid secretion secondary to gastric resection, use of medications that suppress gastric acid, or gastric infection with Helicobacter pylori is the most common cause of which of the following? A) Thiamine deficiency B) Riboflavin deficiency C) Vitamin B12 deficiency D) Folic acid deficiency

Ans: C Feedback: Factors that increase the risk of vitamin B12 deficiency include gastric resection, use of medications that suppress gastric acid secretion, and gastric infection with H. pylori.

The nurse is aware that vitamins are organic compounds that differ in function and availability. When discussing the difference with a client, which of the following statements would best describe vitamins? A) Vitamins are composed of long chains of molecules linked together. B) Vitamins provide energy. C) Vitamins are susceptible to destruction by factors such as heat, air, and light. D) Vitamins exist in only one active form.

Ans: C Feedback: Vitamins are susceptible to destruction and subsequent loss of function due to vulnerability to heat, light, oxidation, acid, and alkalis. Vitamins are individual molecules. They do not provide energy but are needed for metabolism of energy. They are extremely complex chemical substances that differ widely in structure.

The clinic nurse is conducting an education session for clients who are taking anticoagulants. Which of the following should the nurse stress to the clients? A) They should avoid all sources of vitamin D. B) They should maintain a consistent intake of vitamin D. C) They should avoid all sources of vitamin K. D) They should maintain a consistent intake of vitamin K.

Ans: D Feedback: Anticoagulants interfere with hepatic synthesis of vitamin K-dependent clotting factors. Clients should try to maintain a consistent intake so that the effect on coagulation time is as constant and predictable as possible.

Beta-carotene is an important vitamin for vision. To help ensure a client incorporates this in his diet, which of the following foods should the nurse encourage the client to eat? A) Citrus juice B) Egg yolks C) Vegetable oils D) Winter squash

Ans: D Feedback: Beta-carotene is found in "greens" (turnip, dandelion, beets, collard, mustard), spinach, kale, broccoli, carrots, peaches, pumpkin, red peppers, sweet potatoes, winter squash, mango, apricots, and cantaloupes.

During a nutrition class, a group of individuals learn that vitamins can exist in more than one form and have more than one function. Which of the following vitamins exists in more than one form? A) Vitamin B12 B) Thiamin C) Riboflavin D) Vitamin A

Ans: D Feedback: In its preformed state, vitamin A exists as an alcohol (retinol), aldehyde (retinaldehyde), or acid (retinoic acid). The term vitamin A also includes provitamin A carotenoids.

A client is having difficulties understanding the difference between fat-soluble and water-soluble vitamins. The nurse explains which of the following is one of those differences? A) Fat-soluble vitamins must be consumed daily. B) Fat-soluble vitamins are absorbed directly into the bloodstream. C) Fat-soluble vitamins are excreted in the urine when consumed in excess of need. D) Fat-soluble vitamins are stored, primarily in the liver and adipose tissue.

Ans: D Feedback: There are multiple differences between fat-soluble and water-soluble vitamins. Fat-soluble vitamins are stored, primarily in the liver and adipose tissue. The remainder choices are true of water-soluble vitamins.

Thiamin acts as a coenzyme when the body metabolizes carbohydrates. It also has another important function. What is that other function? A) Thiamin is important in the metabolism of fats. B) Thiamin is important in the digestive process. C) Thiamin is important in liver functioning. D) Thiamin is important in nervous system functioning.

Ans: D Feedback: Thiamin (vitamin B1) is a coenzyme in the metabolism of carbohydrates and branched-chain amino acids. In addition, thiamin is important in the nervous system functioning.

Some chemical reactions within the body create free radicals. These free radicals destroy cells in our body. Some vitamins act as antioxidants to prevent this destruction of cells by free radicals. Which vitamin is a major antioxidant? A) Vitamin B6 B) Thiamin C) Folate D) Vitamin C

Ans: D Feedback: Vitamins that function as major antioxidants are vitamin C, vitamin E, and beta-carotene. Each has a slightly different role in the body.