Chapter 8 book notes Flashcards
1
Q
Vitamins
A
-potent, essential, non-kcaloric, organic nutrients needed from foods in trace amounts.
-help perform functions that promote growth, reproduction, and maintience of health and life.
2
Q
How to vitamins differ from carbs, fats, & proteins?
A
-structure: vitamins are individual units, they are not linked together.
-function: do not yield energy, but assist enzymes in release of energy.
-dietary intakes: vitamins are consumed in micrograms or milligrams, this is why they are known as micronutrients.
3
Q
The only disease a vitamin will cure is the one…
A
-caused by a deficiency of that vitamin.
4
Q
Vitamin A deficiency can cause=
Lack of naicin can cause=
Lack of vitamin D can cause=
A
-blindness
-dementia
-impede bone growth
5
Q
Are vitamin supplements as good as vitamin rich foods?
A
-NO; vitamin supplements do not offer the many benefits that come from vitamin rich foods.
6
Q
What 2 vitamins fall below recommended intakes?
A
-vitamin D
-folic acid (pregnant women)
7
Q
Fat soluble vitamins:
A
-Vitamin A, D, E, & K
8
Q
Water soluble vitamins:
A
B vitamins: thiamin, riboflavin, niacin, pantothenic acid, Biotin, Vitamin B6, folate, Vitamin B12, & vitamin C.
9
Q
Amount of vitamins available from food depends on two factors:
A
1)quantity provided by a food
2)amount absorbed & used by body (bioavailability)
10
Q
bioavailability
A
the rate and extent to which a nutrient is absorbed and used.
11
Q
Determining bioavailability depends on these factors:
A
-efficiency of digestion & time of transit through GI tract
-previous nutrient intake & nutrition status
-other foods consumed at same time
-method of food preparation (raw or cooked)
-source of nutrient (natural, synthetic, or fortified).
12
Q
Precursors
A
-vitamins available from foods in inactive forms known as precursors, (provitamins)
-once inside body, precursor is converted to the active form of vitamin
13
Q
So when measuring a person’s vitamin intake it is important to count both the actual amount of a vitamin and ..
A
-potential amount available from its precursors.
14
Q
Because vitamins are organic compounds..
A
-they can be readily destroyed during processing.
-so processed foods should be handled with care during storage and in cooking.
15
Q
How can these vitamins be destroyed?
Thiamin=
Riboflavin=
Vitamin C=
A
-prolonged heating
-can be destroyed by UV rays of sun or fluorescent lights, so if stored in transparent glass, vitamin will be destroyed.
-oxygen destroys vitamin C so losses occur when food is cut, processed, and stored.
16
Q
How minimize nutrient losses of vitamins:
A
-prevent enzymatic destruction; refrigerate most fruit, veggies, and jucies to slow down breakdown.
-protect from light & air
-prevent heat destruction or losses in water
17
Q
Fat soluble vitamins
A
-Vitamin A,D,E, &K
-body absorbs them the same way as it absorbs lipids
-once absorbed they are stored in the liver & fatty tissues until body needs them.
-can build up to toxic conditions
18
Q
What is the first fat-soluble vitamin to be recognized?
A
-Vitamin A and its precursor beta-carotene.
19
Q
Roles of vitamin A:
A
-VERSATILE VITAMIN!!!
-gene expression, vision, cell differentiation, immunity, & reproduction & growth
20
Q
3 active forms of vitamin A in the body:
A
1)Retinol: supports reproduction and is major storage and transport form of vitamin
2)Retinal: active in vision
3)Retinoic acid: acts as a hormone, regulating cell differentiation, growth and embryonic reproduction
21
Q
Retinol is converted by cells to make?
A
-retinoic acid or retinal as needed
22
Q
retinol-binding protein
A
-a special transport protein
-picks up retinol from liver, where it is stored, and carries it in the blood.
23
Q
Vitamin A in gene expression
A
-hundreds of genes are regulated by retinoic acid.
-may affect the development & treatment of certain cancers
24
Q
Vitamin A plays two roles in the eye:
A
-it helps maintain a healthy, crystal clear outer window (cornea)
-helps in light detection at the retina
25
When vitamin A is lacking what happens to the eye?
-the eye has difficulty adapting to changing light levels
26
Night blindness
-symptom of vitamin A deficiency
-at night, after eye has adapted to darkness, a flash of bright light is followed by a brief delay before eye can see again.
27
Vitamin A in protein synthesis and cell differentiation
-present in the skin and linings of organs to promote protein synthesis and cell differentiation.
28
cell differentiation
-process that allows each type of cell to mature so that it is capable of performing a specific function.
29
Epithelial tissue linings found in body
-skin
-covers the cornea
-lining of eyelids & sinus passageways.
-linings of mouth, stomach, intestines, lungs, and passages leading to them,
-lining of bladder, uterus, vagina
30
What substance does epithelial cells secrete to coat the tissues and protect them from invasive microorganisms?
-mucus
31
Vitamin A helps to maintain the integrity of what in cell differentiation?
-epithelial cells
32
Vitamin As role in immunity
-"anti-infective" vitamin
-help regulate genes involved in immunity
33
Vitamin A role in reproduction, growth, & development:
-IN women=
-in men=
-during pregnancy=
-in men it helps with sperm development
-in women it promotes fetal growth & development
-in pregnancy vitamin A is transferred to fetus and is essential in development of nervous system, lungs, kidneys, skeleton, eyes, & ears.
34
Besides being a precursor of Vitamin A, what other role does beta-carotene play?
-antioxidant; a compound that protects other compounds from attack by oxygen.
35
What can too much oxygen trigger in the body? (cell wise)
-free radicals
-start chain reactions in cell membranes that damage cell structures and impair cell functions
36
Oxidative and free radical damage can lead to what?
-early stages of cancer & heart disease
-age related blindness, Alzheimer's, arthritis, cataracts, diabetes, and kidney disease.
37
Besides beta-carotene, what else is considered a dietary antioxidants?
-Vitamin E, C, mineral selenium, and many phytochemicals.
38
Has there been a recommended intake value for beta-carotene established by the DRI?
-NO
39
How much vitamin A can be stored in the body & where?
-up to a years supply
-90% stored in the liver
40
Deficiency symptoms of vitamin A would not begin to appear until?
-1-2 years
41
What is impaired in vitamin A deficiency?
-cell differentiation & maturation
42
Vitamin A deficiency & its affect in the eye
-process leads to drying and hardening of the cornea , which may progress to permanent blindness, also known as XEROPTHALMIA.
43
What is the major cause of preventable blindness in children worldwide?
-vitamin a deficiency causing half a million of children to lose their eyesight every year.
44
Stages of xerophthalmia:
-cornea becomes dry and hard because of lack of mucus production (xerosis)
-xerosis then becomes keratomalacia, the softening of the cornea that leads to irreversible blindness.
45
Vitamin A deficiency and how it affects the skin:
-epithelial cells flatten and begin to produce keratin (hard, inflexible protein of hair & nails).
-makes skin dry, rough, scaly, & hard.
46
Keratinization
-accumulation of keratin that makes a lump around each hair follicle.
47
Vitamin A and how it affects the mouth:
-results in drying & hardening of salivary glands, making them susceptible to infection.
48
Vitamin A deficiency and its affect in stomach & intestines lining:
-secretions of mucus in stomach and intestines are reduces, hindering normal digestion & absorption of nutrients.
49
Vitamin A deficiency and bodys defensive barriers
-makes a person more susceptiable to infections
-EX- measles kills 384 children each day, due to diarrhea and pneumonia, large doses of Vitamin A can reduce the risk of dying from these infections
50
What concentrated amounts of preformed vitamin A (active form of vitamin) foods can lead to vitamin A toxicity?
-foods derived from animals, fortified foods, or supplements
-PLANTS ONLY CONTAIN BETA-CAROTENE, AND DOES NOT CONVERT VITAMIN A RAPID ENOUGH TO CAUSE TOXICITY.
51
Overdoses (toxic levels) of vitamin a damage the same body systems & exhibit symptoms like that in?
-vitamin a deficiency
52
Who is most vulnerable to vitamin A toxictiy?
-children
53
What foods that children eat contain 100% or more of the recommended daily intake of vitamin A?
-breakfast cereals, instant meals, fortified milk, and chewabale candy like vitamins.
54
RDA recommendation for daily vitamin A intake for men and women:
- men= 900 micrograms
-women=700 micrograms
55
Excessive vitamin A can also pose a teratogenic risk, which is..?
-an abnormal fetal development and birth defects.
-too much vitamin A during pregnancy injure the spinal cord and other tissues of developing fetus
56
UL (tolerable upper intake level) for women of childbearing age
-3000 micrograms
57
How much of vitamin A do multivitamins supplements typically provide?
-1500 micrograms, which is more than people need
58
Vitamin A prescription and acne
-directly applied to skin surface, will help relieve acne symptoms but not cure acne.
59
Beta-carotene is measured not by micrograms but by?
-retinol activity equivalents (RAE), which expresses the amount of retinol the body actually derives from a plant after conversion
60
one microgram of retinol counts as 1 RAE, as well as ?micrograms of dietary beta-carotene?
-12
61
Overconsumption of beta carotene is never hazardous but it can do what to the skin?
-turn it bright yellow; this is because beta-carotene builds up in fat just beneath the skin and imparts a yellowish cast to the skin.
62
Overconsumption of beta-carotene supplements can be..
-harmful, especially to smokers.
63
Preformed (active form) vitamin A is found only in what kinds of food?
-foods of animal origin
64
Foods richest in vitamin A are:
-liver and fish oil, but milk, cheese, eggs, and butter and fortified cereals are also good sources.
65
Because vitamin A is fat soluble is it lost in milk when it is..
-skimmed, so milk that is fat free, reduced fat, or low fat have vitamin A
66
Margarine provides same amount of vitamin A as ?
-butter
67
Additional vitamin A rich foods:
-cooked spinach and carrots, baked sweet potato, cooked bok choy, and apricots
68
Beta carotene rich foods
-many foods from plants contain beta-carotene, which help give them their color
-orange pigments of fruit & veggies & dark green veggies
69
Bright orange veggies rich in beta carotene:
-carrots, sweet potatoes, pumpkins, cantaloupe, and apricots.
70
Dark green veggies rich in beta cartoene:
-spinach, broccoli
71
Vitamin D is different from the other nutrients in the body because...
-it can synthesize significant quantities with the help of sunlight.
-it is not a essential nutrient, with enough sun people do not need vitamin D from food
72
Vitamin D is also known as...
-calciferol
73
Two major forms of Vitamin D:
1) Vitamin D2, which is obtained from plant foods
2)Vitamin D3, which is obtained from animal foods and synthesis in skin
-BOTH MUST BE ACTIVATED BEFORE BEING FUNCTIONAL
74
Vitamin Ds metabolic conversions:
-liver manufactures a vitamin D precursor which migrated to the skin, where it is then converted to a second precursor with help of the suns UV rays.
-then the liver & kidneys alter the second precursor to produce the active vitamin.
75
Whether vitamin D is made from the sun or food, the same two conversions are needed from the liver and kidney so diseases of the kidney and liver can impair..
-vitamin D metabolic conversions
76
Vitamin D is actually a..
-hormone; a compound manufactured by one organ of the body that has effects on another.
77
Best known vitamin D target organs are:
-small intestines, kidneys, and the bones
78
Vitamin D in the brain and nerve cells:
-protects against cognitive decline and may help slow the progression of Parkinson's disease
79
Vitamin D in muscle cells
-encourages muscle strength and function in children and preserves strength in adults
80
Vitamin D and the immune system
-signals cells in the immune system to defend against infectious diseases.
81
Vitamin D and obesity:
-may also help regulate the cells of the adipose tissue in ways that might contribute to obesity.
-FUTHER RESEARCH IS NEEDED
82
Vitamin D insufficiency is common and it affects what percentage of the population?
-18%
-most vulnerable are older adults, especially women and black people, obese, physically inactive, or smokers.
83
Vitamin D deficiency can cause what disease?
-Rickets, affects more than half of children in some countries.
-uncommon in US but not unknown.
84
rickets
-in children
-bones fail to calcify, causing growth restriction and skeletal abnormalities.
-bones become so weak that they bend when they have to support bodys weight.
85
What is an obvious sign of rickets?
-bowed legs
-also beaded ribs
86
DRI recommends that all infants, adolescents, and children consume how much vitamin D?
-15 micrograms
87
In adults, vitamin D deficiency leads to..?
-osteomalacia (painful bone disease, softening of bones, ADULT RICKETS)
-osteoporosis (adult bone loss)
88
Vitamin D toxicity:
-MOST TOXIC EFFECT OF ALL VITAMINS
-raises concentration of blood calcium, which can cause stones especially in kidneys
-calcification can also harden the blood vessels, especially dangerous in brain, lungs, and heart.
89
DRI UL for vitamin D:
-50 micrograms per day.
90
Does using sunscreen prevent synthesis of Vitamin D?
-No it just slows down
91
Vitamin D in foods:
-few animal foods (eggs, liver, some fatty fish, and fortified milk).
-margarine
-infant formula, breastmilk low in vitamin D
-few plant foods contain vitamin D (expect margarine and soy milk)
92
DRI vitamin D recommendations:
-intake recommendations increase with age, due to increasing in age increases risk of vitamin D deficiency.
93
Vitamin E's discovery:
-researchers discovered a compound in vegetable oils necessary for reproduction in rats.
-compound was named tocopherol, now known as vitamin E.
94
Vitamin E as an antioxidant:
-protects other substances from oxidation by being oxidized itself.
-also is effective in preventing oxidation of polyunsaturated fatty acids.
95
Vitamin E exerts a antioxidant effect on which organs?
-the lungs; where they are exposed to high concentrations of oxygen
-the heart; by protecting LDL from oxidation and reducing inflammation.
96
Vitamin E deficiency’s classic symptom: Erythrocyte hemolysis
-when blood concentrations of vitamin E fall below certain critical level, the red blood cells tend to break open and spill their contents, because the PUFA in membranes oxidize.
97
where is erythrocyte hemolysis seen?
-in premature infants born before transfer of vitamin E from mother to fetus that takes place in the last weeks of preganacy.
98
Vitamin E deficiency symptoms seen in adults:
-loss of muscle coordination and reflexes
-vision
-speech
99
Vitamin E toxicity:
-very rare and not as serious
-but high vitamin E interferes with blood clotting action of vitamin K, which leads to a hemorrhage.
100
UL for vitamin E
-1000 milligrams
-65times greater than the recommended intake for adults (15 milligrams).
101
Food sources rich in vitamin E
-vegetable oils, nuts & seeds (sunflower seeds &n almonds) and wheat germ
-margarine, salad dressings, and shortenings.
102
Vitamin K is known for its role:
-blood clotting
-gets name from danish word koagulation (coagulation or "clotting")
103
What is involved in blood clotting?
-13 different proteins and the mineral calcium
-Vitamin K is essential for the activation of several of these proteins (prothrombin)
104
What happens when blood clotting factors are lacking?
-hemorrhagic disease, which bleeding goes unchecked
-hemorrhaging is not always caused by vitamin K dificiency.
105
Can vitamin K be obtained from a nonfood source?
-yes
-bacteria in the intestinal tract synthesize vitamin k that the body can absorb
106
Vitamin K deficiency is rare, but it can occur in two circumstances:
1)conditions of fat malabsorption
2)medications interfere with vitamin Ks synthesis and action in body
107
What medications interfere with synthesis of vitamin K in the body?
-antibiotics kill the vitamin K producing bacteria in intestine
-anticoagulant medications interfere with vitamin K metabolism and activity.
108
Vitamin K in newborns:
-infant is born with a sterile digestive tract, so weeks pass before the Vitamin K producing bacteria become fully established in infants intestines.
-so a single dose of vitamin K (in water soluble form) is given at birth to prevent hemorrhagic disease in newborn.
109
Vitamin K toxicity:
-very rare, no adverse effects have been reported so UL has not been established.
110
High doses of vitamin K can reduce?
-effectiveness of anticoagulant medications used to prevent blood clotting.
-people taking these medications should eat vitamin K rich foods.
111
Vitamin K in foods:
-green leafy veggies, members of cabbage family, some vegetable oils.
-iceburg lettuce and green beans provide small amounts.
112
Water soluble vitamins:
-vitamins B and C
-found in watery compartments of food and distributed into water filled compartments of body.
-easily absorbed into bloodstream and easily excreted if blood concentrations are too high.
113
Vitamin B do not give people energy, they only...?
-help the body use that fuel
114
Vitamin B is known for being a good..
-coenzyme; a small molecule that combines with enzyme to make it active.
115
Active forms of 5 of the b vitamins help participate in the release of energy from carbs, fat and protein. what are they?
-thiamin, riboflavin, niacin, pantothenic acid, and biotin.
116
A coenzyme containing vitamin B6 assist enzymes that:
A coenzyme containing vitamin B12 and folate assist:
-metabolize amino acids
-help cells multiply (red blood cells & GI tract cells).
117
the only two cases that have dietary deficiencies associated with single B vitamin:
1)beriberi
2)Pellagra
118
Beriberi
- in southeat asia when custom polishing of rice was widespread
-rice bran was principle source of thiamin, so when bran was removed to make rice whiter, beriberi spread
119
pellagra
-widespread in southern US in 20th century
among people who had a low protein diet with corn as a staple grain.
-did not supply enough niacin nor tryptophan.
120
If a staple food of a region is made from refined grain then.... what is a refined grain?
-vitamin B deficiencies are likely
-a grain in which the husk, bran, and germ have been removed leaving only a endosperm.
121
How to protect people from deficiencies of vitamin B?
-add nutrients to their staple food, process known as fortification/enrichment.
122
Thiamin (Vitamin B1) chief function:
-part of a coenzyme used in energy metabolism
-critical for functioning of nerves and muscles
123
Thiamin deficiency
-in homeless or malnourished people
-people risk thiamin deficiency when get most of their energy from empty k-caloric foods and beverages (ALCOHOL)
124
Many alcoholics are thiamin deficient and develop:
-wernicke-korsakoff syndrome
125
Thiamin toxicity
-none reported
-no UL
126
Food sources of thiamin
-enriched, fortified, or whole grain products
-pork
127
Riboflavin (vitamin B2) chief function:
-part of coenzymes used in energy metabolism
-women carrying one or more fetus need a lot of riboflavin
-extremely active people need extra riboflavin
128
riboflavin deficiency symptoms
-inflammation of the mouth, skin, and eyelids
-sensitivity to light
-sore throat
129
riboflavin toxicity
-none reported
-no UL set
130
riboflavin food sources:
-milk products (provide 50%)
-whole grain products (cereal and breads)
-liver and heart
-green veggies
131
riboflavin and effects of light
-riboflavin is light sensitive
-the UV rays of the sun or fluorescent lamps can destroy it
-because of this milk is sold in cardboard or opaque plastic containers.
132
Niacin (vitamin B3) chief function
-part of coenzyme used in energy metabolism
133
Niacin can be made from:
-protein
-amino acid tryptophan can be converted to niacin in body
134
how many milligrams of tryptophan yield 1 milligram of niacin?
-60
135
Recommended intakes are therefore stated as?
-niacin equivalents (NE)
136
niacin deficiency
pellagra (diarrhea, dermatitis, and dementia).
137
Niacin toxicity (PHARMACOLOGICAL EFFECTS)
-ONLY FROM SUPPLEMENTS
produces niacin flush: dilates capillaries of skin and cause tingling
-liver damage
-glucose intolerance
138
niacin in foods
-meat, poultry, fish, legumes and enriched whole grains and bread
-mushrooms, asparagus, and potatoes
139
Biotin chief function
-part of coenzyme used in energy metabolism that carries carbon dioxide
140
Biotin deficiency
-rare
-seen in adults who are fed by vein without biotin supplmentation.
-skin rash, hair loss
141
biotin in foods
-widespread in foods
-GI bacteria synthesis
142
Pantothenic acid chief function
-part of coenzyme used in energy metabolism
-key enzyme that makes it possible for energy to be released from nutrients
-stimulates growth
143
Pantothenic acid deficiency
-digestive and neurological distrubances
144
panothenic acid in foods
-widespread in foods
145
Vitamin B6 chief functions
-part of coenzymes used in amino acid, fatty acid, carb, and protein metabolism
-aids in conversion of tryptophan to niacin
-synthesis of hemoglobin and neurotransmitters
-regulation of blood glucose
146
Vitamin B6 deficiency
-general symptoms
-weakness, depression, confusion, irritability, flaky dermatitis
147
vitamin B6 toxicity
-nerve degeneration (numb feet and hands)
-inability to walk
148
UL for vitamin B6
-100 milligrams
149
Vitamin B6 foods
-meat, fish, poultry, potatoes, legumes
150
Folate chief functions:
-Activates vitamin B12
-active in cell division (red blood cells and digestive tract cells)
151
During periods of rapid growth and cell division, such as ???, folate needs increase and deficiency is especially likely.
-pregnancy and adolescence
152
Folate deficiency: what are the first two symptoms?
-a type of anemia and GI tract deterioration
153
Folate and its interaction with drugs and alcohol
-alcohol impairs folates absorption and increases its excretion
-asprin & oral contraceptives & smkojng
154
Folate prevents...
-neural tube defects
-folate supplements must be taken before conception and continued throughout 1st trimester of pregnancy to prevent NTD.
155
Childbearing age women should consume how much folic acid daily?
-400 micrograms
156
Folate food sources:
-fortified grains, leafy greens, legumes, seeds, and liver
157
Folate toxicity symptoms:
-masks vitamin B12 deficiency
158
Special relationship between Vitamin b12 and folate:
-vitamin B12 assists folate in cell division.
159
Vitamin B12 chief function
-activates folate
-helps with cell division (red blood cells and digestive cells)
-protects nerve cells
160
Vitamin B12 & Folate and their role in cell division
-b12 stands by to accept carbon groups from folate and folate removes them from other compounds.
161
Which cells are first to be affected by deficiency of folate or b12?
-red blood cells
162
Macrocytic anemia
-large, immature red blood cells
-deficiency of vitamin B12 or folate
163
Vitamin B12 deficiency symptoms
-anemia
-nerve damage and paralysis
164
Absorption of B12 requires:
-intrinsic factor
-a compound made by stomach from instructions from genes.
-attaches itself to vitamin to be absorbed in bloodstream.
165
Atrophic gastritis
-inability to produce enough stomach acid and intrinsic factors to support B12 absorption
166
Pernicious anemia
-anemia developed by lack of intrinsic factor
167
Vitamin B12 food sources:
-foods dervied from animals
168
Vitamin C (ascorbic acid) chief function:
-synthesis of collagen, carnitine(transporter of fatty acids), hormones, neurotransmitters
-antioxidant
169
Vitamins C role in collagen formation:
-helps form collagen
-important in artery walls and capillaries
170
collagen
-single most important protein of connective tissue
171
Vitamin C as a antioxidant:
-protects water soluble substances from being oxidized by being oxidized themselves
-protects iron from oxidation so it enhances iron absorption
172
What is the first to show signs of vitamin C deficiency?
-blood vessels
173
Vitamin C deficiency symptoms
-scurvy (bleeding gums, hemorrhages, joint pain).
-no scar tissue forms
174
How many milligrams of Vitamin C does it take to prevent scurvy?
-10 milligrams
175
Vitamin C toxic symptoms
-diarrhea, GI distress
-people with gout need to be careful
176
Vitamin C food sources
-citrus fruits
-cabbage type veggies
- dark green veggies
=papayas, mangoes, etc.
177
Vitamin C RDA intake for men and women:
men=90 milligrams
women=75 milligrams
178
Vitamin C and iron absorption:
-eating foods with vitamin C and iron can double or triple the absorption of iron.
