Chapter 7 Flashcards
(131 cards)
1
Q
vitamin
A
an essential, noncaloric, organic nutrient needed in tiny amounts in the diet
2
Q
what are the fat-soluble vitamins?
A
A, D, E, K
3
Q
what are the water-soluble vitamins?
A
thiamin, riboflavin, niacin, folate, B12, B6, biotin, pantothenic acid, vitamin C
4
Q
precursors
A
compounds that serve as starting materials for other compounds. In nutrition, vitamin precursors are compounds that can be converted into active vitamins. Also called provitamins.
5
Q
Fat-soluble vitamins, like other lipids, are mostly absorbed into…
A
the lymph, and they travel in the blood and within the cells in association with protein carriers. some can get toxic levels
6
Q
are water-soluble vitamins absorbed directly into the bloodstream?
A
yes. the risk of toxicities are not as great because excesses are excreted in the urine
7
Q
which vitamins require bile for absorption?
A
The fat-soluble vitamins
8
Q
do we need to eat fat-soluble vitamins every day?
A
no because they are stored in the liver and fatty tissues after absorption
9
Q
which vitamins kind of act like hormones?
A
vitamins A and D
10
Q
which vitamin protects tissues all over the body from destructive oxidative reactions?
A
vitamin E
11
Q
which vitamin is necessary for blood to clot and for bone health?
A
vitamin K
12
Q
what is vitamin A’s plant-derived precursor?
A
beta carotene
13
Q
how many forms of vitamin A are active in the body?
A
- one is retinol. The cells convert retinol to its other two active forms, retinal and retinoic acid
14
Q
which foods must be converted to active vitamin A before it can be used?
A
Foods derived from plants. Foods derived from animals provide forms of vitamin A that are readily absorbed and put to use by the body
15
Q
what are the roles of vitamin A?
A
gene expression, vision, maintenance of body linings and skin, immune defenses, growth of the body, and normal development of cells. importance for both male and female reproductive functions and for normal development of an embryo and fetus.
16
Q
what’s the DI of vitamin A for men and women?
A
men: 900 ug/day
women: 700 ug/day
17
Q
what’s the tolerable upper intake level for vitamin A?
A
3,000 ug/day
18
Q
deficiency if vitamin A results in…
A
Night blindness, corneal drying (xerosis), and blindness (xerophthalmia); impaired growth; keratin lumps on the skin; impaired immunity
19
Q
what are good sources of Vitamin A?
A
spinach, sweet potato, carrots, fortified milk, apricots, bok choy, beef liver,
20
Q
vitamin A is important for sustaining vision. specifically it acts on the…
A
cornea and retina
21
Q
A more profound deficiency of vitamin A is exhibited when the protein keratin accumulates and clouds the eye’s outer vitamin A–dependent part, the cornea. The condition is known as…
A
keratinization, and if the deficiency of vitamin A is not corrected, it can worsen to xerosis (drying) and then progress to thickening and permanent blindness, xerophthalmia.
22
Q
which form of vitamin A is involved in gene regulation?
A
retinoic acid.
23
Q
vitamin A is needed by which tissues?
A
epithelial tissue
24
Q
which vitamin is involved in the process of cell differentiation?
A
vitamin A
25
what happens if cell differentiation is impaired?
for example, the goblet cells are displaced by keratin, which can lead to infections because it makes the tissue dry, hard, and cracked
26
which vitamin has a reputation as an “anti-infective” vitamin?
vitamin A
27
which vitamin participates in sperm development and supports normal fetal development during pregnancy?
vitamin A
28
which vitamin is crucial for the formation of the spinal cord, heart, and other organs?
vitamin A
29
what are the symptoms of toxic levels of vitamin A?
skin rashes, hair loss, hemorrhages, bone abnormalities, birth defects, fractures, liver failure, death
30
how can you meet your vitamin A need?
by consuming the active form in animal food sources, or by consuming beta-carotene in plants.
31
what are the richest sources of active vitamin A?
liver and fish oil
32
what is a natural sources of yellow coloring?
beta carotene
33
what are the key antioxidant vitamins?
beta-carotene, vitamin E, vitamin C
34
what are some rich sources of beta-carotene?
Carrots, sweet potatoes, pumpkins, mango, cantaloupe, and apricots
35
diets lacking in dark green, leafy vegetables and orange vegetables are associated with the most common form of age-related blindness...
macular degeneration. impairs the central focus
36
carotenoids
members of a group of pigments in foods that range in color from light yellow to reddish orange and are chemical relatives of beta-carotene.
37
vitamin A activity for precursors is measured in...
retinol activity equivalents (RAE)
38
how many micrograms of beta-carotene equals 1 microgram of retinol?
12
39
what are poor sources of beta-carotene?
red beets, red cabbage, yellow corn
40
which vitamin has nutrients that interact to regulate blood calcium and phosphorus concentrations?
vitamin D
41
what are the key vitamins, minerals and energy nutrient needed for bone health?
vitamin D, vitamin K, vitamin C, calcium, phosphorus, magnesium, fluoride, protein
42
what happens when blood calcium concentration is low?
vitamin D acts on three body locations to raise it. First, the skeleton serves as a vast warehouse of stored calcium that can be tapped when blood calcium begins to fall. Second, the digestive tract increases absorption of calcium from food. Third, the kidneys recycle calcium that would otherwise be lost in urine.
43
rickets
the vitamin D–deficiency disease in children; characterized by abnormal growth of bone and manifested in bowed legs or knock-knees, outward-bowed chest deformity (pigeon chest), and knobs on the ribs.
44
osteomalacia
the adult expression of vitamin D–deficiency disease, characterized by an overabundance of unmineralized bone protein
45
osteoporosis
a reduction of the bone mass of older people in which the bones become porous and fragile
46
How can excess fat in the body cause low vitamin D in the blood?
extra fat tissue requires a great deal of extra blood flow, so vitamin D, even if amply provided, may become diluted in the larger blood volume of overweight people. at-soluble vitamin D may be taken up and sequestered in the fat tissue of overweight people, making it less available to the bloodstream
47
which is the most potentially toxic vitamin?
vitamin D
48
how does high intakes of vitamin D affect the body?
kidney and heart function decline, blood calcium spins further out of control
49
what are the symptoms of high levels of vitamin D?
high blood calcium, nausea, fatigue, back pain, irregular heartbeat, and increased urination and thirst
50
what's the vitamin D recommendations?
ages 1-70 need 15 micrograms. 71 and up need 20 micrograms
51
what's the UL for vitamin D?
100 micrograms
52
what are goos sources of vitamin D?
salmon or mackerel, sardines, enriched cereal, tuna, fortified milk, cod-liver oil
53
can mushrooms be rich sources of vitamin D?
only if they were grown in sunlight
54
tocopherol is also known as...
vitamin E
55
what are the 4 tocopherol compounds?
alpha, beta, gamma, and delta
56
which compound is the gold standard for vitamin E?
alpha-tocopherol
57
is vitamin E an antioxidant?
yes. it quenches free radicals and reduces inflammation
58
who usually has deficiencies of vitamin E?
may occur in people with diseases that cause fat malabsorption or in infants born prematurely. Disease or injury of the liver, gallbladder, or pancreas
59
what happens if infants don't get sufficient vitamin E?
the infant’s red blood cells rupture (erythrocyte hemolysis), and the infant becomes anemic.
60
what are the symptoms of vitamin E deficiency?
loss of muscle coordination, loss of normal reflexes, and impaired vision and speech
61
which vitamin augments the effects of anticoagulant medication used to oppose unwanted blood clotting?
vitamin E
62
what's the UL for vitamin E?
1000 milligrams
63
what's the DRI for vitamin E?
15 milligrams
64
what are good sources of vitamin E?
wheat germ, safflower oil, sunflower seeds, canola oil, mayonnaise,
65
which vitamin is easily destroyed by heat?
vitamin E
66
what's the main function of vitamin K?
to help activate proteins that help clot the blood.
67
which medicine interferes with vitamin K's clot-promoting action?
warfarin
68
vitamin K is also necessary for...
synthesis of key bone proteins
69
can vitamin K be obtained from nonfood sources?
yes. intestinal bacteria normally reside in the intestines, and some of them synthesize vitamin K
70
since newborn infants have sterile intestinal tracts, what vitamin is given to them at birth?
vitamin K
71
how does toxic doses of vitamin K affect the body?
Toxicity induces breakage of the red blood cells and release of their pigment, which colors the skin yellow. A toxic dose of synthetic vitamin K causes the liver to release the blood cell pigment (bilirubin) into the blood (instead of excreting it into the bile) and leads to jaundice.
72
what's the DRI of vitamin K for men and women?
men: 120 ug/day
women: 90 ug/day
73
what are good sources of vitamin K?
soybeans, spinach, cabbage, salad greens, asparagus, kale
74
water soluble vitamins
Vitamin C and the B vitamins dissolve in water. In food, water-soluble vitamins easily dissolve and drain away with cooking water, and some are destroyed on exposure to light, heat, or oxygen during processing.
75
scurvy
the vitamin C–deficiency disease. collagen is broken down
76
vitamin C has what kind of acid?
ascorbic acid
77
vitamin C is best known foe what?
maintaining the connective tissues and as an antioxidant.
78
collagen depends on which vitamin for its activity?
vitamin C
79
vitamin C protects what mineral from oxidation and promotes its absorption?
iron
80
prooxidant
a compound that triggers reactions involving oxygen.
81
In drug-like doses, vitamin C may mimic a weak...
antihistamine drug
82
what are the symptoms of scurvy?
loss of appetite, growth cessation, tenderness to touch, weakness, bleeding gums, loose teeth, swollen ankles and wrists, and tiny red spots in the skin where blood has leaked out of capillaries
82
what are the symptoms of scurvy?
loss of appetite, growth cessation, tenderness to touch, weakness, bleeding gums, loose teeth, swollen ankles and wrists, and tiny red spots in the skin where blood has leaked out of capillaries
83
what's the problem with taking large doses of vitamin C?
People taking anticlotting medications may unwittingly counteract the drug’s effect, Those with kidney disease, a tendency toward gout, or abnormal vitamin C metabolism are prone to forming kidney stones, nausea, abdominal cramps, excessive gas, and diarrhea
84
what's the UL for vitamin C?
2,000 milligrams. minimum is 10 milligrams
85
what's the RI of vitamin C for men and women?
men: 90mg/day
women: 75mg/day
smokers: add 35mg
86
what are good sources of vitamin C?
sweet potato, grapefruit, brussel sprouts, sweet red pepper, bok choy, strawberries, broccoli, green pepper, orange juice
87
why do we have to treat fruit and vegetables gently to get the most vitamin C?
because Vitamin C is vulnerable to heat and destroyed by oxygen
88
which vitamin function as parts of coenzymes?
vitamin B
89
coenzyme
a small molecule that works with an enzyme to promote the enzyme’s activity.
90
active forms of five of the B vitamins—thiamin, riboflavin, niacin, pantothenic acid, and biotin- help with what?
participate in the release of energy from carbohydrate, fat, and protein.
91
what does vitamin B6 do?
helps the body use amino acids to synthesize proteins
92
what do folate and vitamin B12 do?
help cells to multiply, which is especially important to cells with short life spans that must replace themselves frequently
93
what are the symptoms of B vitamin deficiency?
nausea, severe exhaustion, irritability, depression, forgetfulness, loss of appetite and weight, pain in muscles, impairment of the immune response, loss of control of the limbs, abnormal heart action, severe skin problems, swollen red tongue, cracked skin at the corners of the mouth, and teary or bloodshot eyes
94
thiamin
critical role in the energy metabolism of all cells. occupies a special site on nerve cell membranes.
95
what's the thiamin-deficiency disease?
beriberi. characterized by loss of sensation in the hands and feet, muscular weakness, advancing paralysis, and abnormal heart action.
96
alcohol abuse often leads to a severe form of thiamin deficiency called...
Wernicke-Korsakoff syndrome.
symptoms: apathy, irritability, mental confusion, disorientation, memory loss, jerky eye movements, and a staggering gait
96
alcohol abuse often leads to a severe form of thiamin deficiency called...
Wernicke-Korsakoff syndrome.
symptoms: apathy, irritability, mental confusion, disorientation, memory loss, jerky eye movements, and a staggering gait
97
what's the DRI for thiamin?
men: 1.2 mg
women: 1.1 mg
98
what are good sources of thiamin?
waffle, green peas, pork chop, enriched pasta, black beans, baked potato, sunflower seeds, enriched cereal, enriched wheat bagel
99
which process makes many ultra=processed foods?
extrusion
100
what destroys riboflavin?
UV light and irradiation. that's why milk is sold in cardboard or opaque plastic containers
101
what's the DRI for rboflavin?
men: 1.3 mg
women: 1.1 mg
102
what are good sources of riboflavin?
spinach, enriched cereal, cottage cheese, beef liver, mushrooms, pork chop, yogurt, milk
103
what's the niacin-deficiency disease?
pellagra. symptoms are the 4 D's. diarrhea, dermatitis, dementia, and, ultimately, death.
104
what's the most common side effect of large doses of niacin?
the “niacin flush,” a dilation of the capillaries of the skin with perceptible tingling that can be painful.
105
what amino acid can be converted to niacin?
tryptophan
106
what's the DRI for niacin?
men: 16 mg
women: 14 mg
UL: 35 mg
107
what are good sources of niacin?
baked potato, pork chop, chicken breast, mushrooms, enriched cereal, tuna
108
folate works with what other vitamin to produce rbc?
vitamin B12
109
which vitamin is most likely to interact with medications?
folate
110
neural tube defects (NTD)
a group of abnormalities of the brain and spinal cord apparent at birth and caused by interruption of the normal early development of the neural tube. adequate folate may protect against this
111
what's the absorbable synthetic form of folate?
folic acid
112
$folate could mask a subclinical deficiency of which vitamin?
vitamin B12
113
what's the DRI for folate?
400 ug
UL: 1,000 ug
114
what are good sources of folate?
avocado, asparagus, pinto beans, beef liver, beets, enriched cereal, spinach, lentils
115
if there is a symptom of large, immature red blood cells, which vitamin is the body deficient in?
folate or vitamin B12
116
For vitamin B21, deficiencies most often reflect poor absorption that occurs for one of two reasons:
The stomach produces too little acid to liberate vitamin from food.
Intrinsic factor, a compound made by the stomach and needed for absorption, is lacking.
117
pernicious anemia
anemia a vitamin –deficiency disease, caused by lack of intrinsic factor and characterized by large, immature red blood cells and damage to the nervous system
118
what's the DRI for vitamin B12?
2.4 ug
119
what are good sources of vitamin B12?
pork roast, cottage cheese, sirloin steak, chicken liver, enriched cereal, swiss cheese, tuna, sardines
120
what are the functions of vitamin B6?
Aids in the conversion of tryptophan to niacin.
Plays important roles in the synthesis of hemoglobin and neurotransmitters, the communication molecules of the brain. (For example, vitamin assists the conversion of the amino acid tryptophan to the mood-regulating neurotransmitter serotonin.)
Assists in releasing stored glucose from glycogen and thus contributes to the maintenance of a normal blood glucose concentration.
Plays roles in immune function and steroid hormone activity.
Is critical to normal development of the fetal brain and nervous system; deficiency during this stage causes behavioral problems later.
121
what are symptoms of vitamin B6 deficiency?
weakness, psychological depression, confusion, irritability, insomnia, anemia, greasy dermatitis, convulsions
122
what's the DRI for vitamin B6?
age 19-50: 1.3 mg
UL: 100mg
123
what are good sources of vitamin B6?
sweet potato, banana, beef liver, spinach, chicken breast, baked potato
124
Biotin
A B vitamin. important in energy metabolism. a coenzyme for several enzymes in the metabolism of carbohydrate, fat, and protein. intestinal bacteria release biotin that can be absorbed.
125
pantothenic acid
a component of a key coenzyme that makes possible the release of energy from the energy nutrients. also participates in the synthesis of lipids, neurotransmitters, steroid hormones, and hemoglobin.
125
pantothenic acid
a component of a key coenzyme that makes possible the release of energy from the energy nutrients. also participates in the synthesis of lipids, neurotransmitters, steroid hormones, and hemoglobin.
126
choline
a non-B vitamin. plays important roles in fetal development, particularly in the brain.
126
choline
a non-B vitamin. plays important roles in fetal development, particularly in the brain.
127
what are some other nonvitamins that are needed in the diet?
carnitine, inositol, and lipoic acid
