Test Bank - Chapter 7 Nutrition
Foods rich in phytochemicals include
fruits and vegetables. [Fruits and vegetables are rich sources of phytochemicals. The term phytochemical comes from the Greek word phyton, meaning "plant."]
The hormones that participate in calcium metabolism are
parathyroid and calcitriol. [The hormone form calcitriol acts with two other hormones, parathyroid hormone and the thyroid hormone calcitonin, to stimulate the absorption of calcium in the small intestine.]
The requirement for vitamin E varies by the amount of an individual's
polyunsaturated fatty acid intake. [The requirement for vitamin E varies with the amount of polyunsaturated fatty acids in the diet.]
The vitamin most closely associated with protein metabolism is
pyridoxine. [Vitamin B6 (pyridoxine) has an essential role in protein metabolism and functions in many cell reactions involving amino acids.]
Which of the following diets can help ensure adequate and balanced vitamin intake?
A varied diet composed of all food groups eaten in moderate portions [Eating a well-balanced, varied diet can help ensure adequate and balanced intake by supplying needed nutrients from all the food groups in the proper portion sizes.]
The fat-soluble vitamin responsible for the synthesis of blood-clotting factors by the liver is vitamin
K. [The basic function of vitamin K is in the blood-clotting process. The most well-known vitamin K-dependent blood factor is prothrombin.]
What is the most important source of riboflavin in the United States?
Milk [Milk is the major source of riboflavin.]
A vitamin that behaves more like a hormone than a vitamin is vitamin
D. [Vitamin D is a prohormone made in the skin by sunlight.]
The disease associated with niacin deficiency is
Pellagra. [Pellagra is a disease caused by the lack of niacin. It is characterized by skin lesions along with gastrointestinal, mucosal, neurologic, and mental symptoms. The four Ds associated with pellagra are dermatitis, diarrhea, dementia, and death.]
The vitamin that is destroyed by light is
Riboflavin. [Riboflavin is easily destroyed by light. Milk, a major source of riboflavin, is sold and stored in plastic or cardboard containers to protect it from light exposure.]
Vitamin C deficiency is associated with
Scurvy. [Extreme vitamin C deficiency is associated with scurvy.]
An example of a meal high in vitamin C is
a bacon, lettuce, and tomato sandwich and strawberries. [The best sources of vitamin C are citrus fruits; tomatoes; cabbage and other leafy, green vegetables; berries; melons; peppers; broccoli; potatoes; and yellow vegetables]
Vitamin E protects membranes because it acts as
an antioxidant. [Vitamin E protects membranes by acting as nature's most potent fat-soluble antioxidant. The polyunsaturated fatty acids in lipid membranes are easy for oxygen to break down, and vitamin E can interrupt this oxidation and protect the fatty acids of the cell membrane from damage.]
Phytochemicals act as
antioxidants and hormones. [Phytochemicals have antibacterial effects, act as antioxidants and hormones, and interact with enzymes and DNA replication. The beneficial effects of phytochemicals are believed to result from the synergistic actions of multiple nutrients as opposed to acting as an isolated compound.]
A good food source of niacin is
beef. [Meat is a major source of niacin. The greatest intake of niacin in the United States comes from mixed dishes high in meat, poultry, or fish.]
The best food source of folic acid is
broccoli. [Rich sources of folate are found in liver; green, leafy vegetables; yeast; and legumes. Broccoli would be a high source of folate among the choices.]
The primary function of vitamin D is to regulate the absorption and metabolism of the minerals
calcium and phosphorus. [The primary function of vitamin D is the absorption of calcium and phosphorus. The hormone form calcitriol acts with two other hormones: parathyroid hormone and the thyroid hormone calcitonin. In balance with these two hormones, vitamin D hormone stimulates the absorption of calcium and phosphorus in the small intestine.]
The B vitamin predominantly found in foods of animal origin is
cobalamin. [Because cobalamin occurs as a protein complex in foods, its sources are mostly of animal origin.]
Recommended intakes for vitamin D are difficult to establish because Group of answer choices
exposure to sunlight varies. [Recommended intakes for vitamin D are difficult to establish because of its unique hormone-like nature, the difference in exposure to sun (affected by time spent outside and climate), and limited food sources.]
The function of all B-complex vitamins is to
function as coenzymes. [The B-complex vitamins function as coenzymes that are necessary agents to break down compounds, but they are not consumed in the process.]
An important function of vitamin A is to
help form rhodopsin in the eye. [Vitamin A helps form the visual pigment rhodopsin in the eye. Retinol, the name given to vitamin A, is an essential part of rhodopsin, commonly known as visual purple. This light-sensitive substance enables the eye to adjust to the different amounts of available light.]
A folic acid deficiency induces a form of anemia called
megaloblastic anemia. [Megaloblastic anemia can be caused by a lack of folate.]
Two foods that are commonly fortified with vitamin D are
milk and margarine. [Because milk is a common food and already contains calcium and phosphorus, it is the most practical to fortify with vitamin D. Butter substitutes, such as margarines, are also fortified.]
A vitamin D deficiency in growing children that results in the malformation of skeletal tissue, especially the long bones, is referred to as
rickets. [Rickets is a disease associated with vitamin D deficiency. It is characterized by malformation of skeletal tissue in growing children in which long bones are soft and often bend under the weight of the child.]
Synthesis of the active hormonal form of vitamin D is the result of the combined action of the
skin, liver, and kidney. [Vitamin D production begins in the skin with the help of the sun's ultraviolet rays. The compound made in the skin by sunlight is a prohormone. This irradiated compound, cholecalciferol (calciferol), is in its inactive form. It is then activated by two successive enzymes, first in the liver and then in the kidney, to become the active form, calcitriol.]
The person most at risk for vitamin D deficiency is a
62-year-old woman who lives in a cold climate and rarely goes outdoors. [Vitamin D is synthesized in the skin with exposure to sunlight. People who do not go outdoors may be at higher risk for developing a vitamin D deficiency.]
Spinach, carrots, and sweet potatoes are good sources of
beta-carotene [Carotene is the group name of three red and yellow pigments (alpha-, beta-, and gamma-carotene) found in dark-green and yellow vegetables and some fruits. The body converts beta-carotene to vitamin A.]
The provitamin form of vitamin A that is found in plant pigments is
beta-carotene. [Beta-carotene is the provitamin form of vitamin A found in plant pigments. The body converts it to vitamin A, making it a primary source of the vitamin.]
A toxic level of vitamin D is most likely to result in
calcification of soft tissues. [A toxic level of vitamin D can result in calcification of soft tissues, such as in the kidneys and lungs, as well as fragile bones.]
The active hormonal form of vitamin D is
calcitriol [The active form of vitamin D is calcitriol. Vitamin D is made in the body with the help of the sun's ultraviolet rays. The compound made in the skin by sunlight is a prohormone. This irradiated compound, cholecalciferol (calciferol), is in its inactive form. It is then activated by two successive enzymes, first in the liver and then in the kidney, to become the active form, calcitriol.]
A 62-year-old woman who smokes one pack of cigarettes a day and whose food intake records reveal a minimal intake of vitamin C foods is most likely to be at risk for
easy bruising and pinpoint hemorrhages. [Signs of vitamin C deficiency are tissue bleeding, including easy bruising, and pinpoint skin hemorrhages. Smokers deplete their supply of vitamin C more rapidly than nonsmokers do. Cigarette smoke is a source of environmental free radicals, and vitamin C is needed to break down toxic compounds in cigarette smoke.]
The last organ involved in the production of the physiologically active form of vitamin D is the
kidney. [Cholecalciferol (inactive form found in skin) is activated by two successive enzymes, first in the liver and then in the kidney, to become the active form, calcitriol.]
The three body systems that can be affected by a thiamin deficiency are the
nervous, cardiovascular, and gastrointestinal systems. [The nervous, cardiovascular, and gastrointestinal systems can all be affected by thiamin deficiency. The central nervous system depends on glucose for energy; if thiamin is not present in adequate amounts, sufficient energy cannot be made for the nerves to perform their functions. The heart muscle depends on thiamin as well. Without adequate thiamin, the heart muscle weakens and heart failure results. Thiamin also is necessary for the gastrointestinal tract to function properly. The cells of smooth muscle and secretory glands must have energy to perform their work, and thiamin is a necessary agent for producing that energy.]
A young woman who is interested in becoming pregnant should be counseled on healthy eating choices, especially regarding folate-rich foods, which may help prevent
neural tube defects. [Adequate folate intake before and during pregnancy greatly reduces the risk of neural tube defects in infants.]
A deficiency of vitamin A may result in
night blindness. [Night blindness results from a deficiency of vitamin A. Vitamin A helps form the visual pigment rhodopsin in the eye. Retinol, the name given to vitamin A, is an essential part of rhodopsin, commonly known as visual purple. This light-sensitive substance enables the eye to adjust to the different amounts of available light.]
For a compound to be classified as a vitamin, it must
perform a vital function. [For a compound to be defined as a vitamin, it must be a vital, organic, dietary substance that is not a carbohydrate, fat, protein, or mineral and is necessary in only very small amounts to perform a specific metabolic function or prevent an associated deficiency. It also cannot be manufactured by the body in sufficient amounts to sustain life and must be supplemented by the body.]
In the past, vitamin A content was listed in International Units; it is now listed in
retinol equivalents. [Vitamin A is listed in retinol equivalents. One International Unit of vitamin A equals 0.3 mcg retinol or 0.6 mcg beta-carotene.]
There is a metabolic partnership between vitamin E and
selenium. [Selenium is a trace mineral that works with vitamin E as an antioxidant. A selenium-containing enzyme, glutathione peroxidase, is the second line of defense in preventing oxidative damage to cell membranes. Selenium spares vitamin E by reducing the body's requirement for vitamin E, and vitamin E spares selenium by reducing the body's requirement for selenium.]
A good food source of vitamin K is
spinach. [Vitamin K is found in green leafy vegetables, which provide 50-800 mcg of phylloquinone per 100 g of food. Smaller amounts are found in milk and other dairy, meats, fortified cereals, fruits, and vegetables.]
An alcoholic is most likely to be deficient in
thiamin. [Alcohol inhibits the absorption of thiamin. Alcohol-induced thiamin deficiency causes Wernicke's encephalopathy.]
An athlete who increases his or her intake of pasta will also increase his or her need for
thiamin. [The starch in the pasta would be digested and absorbed as glucose. Thiamin acts a coenzyme factor related to the production of energy from glucose and the storage of energy as fat, making energy available to support normal growth.]
The amino acid that can be converted to niacin in the body is
tryptophan. [Some of the niacin the body requires can be made from the essential amino acid tryptophan. The total requirement in the body for niacin is stated in terms of niacin equivalents to account for both sources.]
Liver is a rich source of
vitamin A (retinol). [Liver is a rich source of preformed, natural vitamin A. Other sources include fish liver oils, egg yolk, butter, and cream.]
Fish liver oils are a good source of
vitamin D [Fish liver oils are a natural source of vitamin D. Some other foods are fortified with vitamin D. Because milk is a common food and already contains calcium and phosphorus, it is the most practical to fortify with this vitamin.]
Sunflower oil is a rich source of
vitamin E. [The richest sources of vitamin E are vegetable oils. Other food sources include nuts, fortified cereals, and avocados.]
