Fat soluble vitamins Flashcards
1
Q
what are the fat soluble vitamins
A
ADEK
2
Q
how are fat soluble vitamins different from water soluble vitamins
A
- Require bile for absorption
- Travel thru lymphatic system within chylomicrons before entering bloodstream
- Many require protein carriers in bloodstream
- Excess stored in liver & adipose tissue
- Not readily excreted
- Greater risk of toxicity
3
Q
Upper limits have been established for what vitamins
A
A,D, and E
4
Q
what is the alcohol form of vitamin A
A
retinol
5
Q
what are is the precursor for vitamin A
A
beta carotene
6
Q
what is carotenoid
A
orange pigment found in plants
7
Q
T/F beta carotene also acts as an antioxidant
A
true
8
Q
how is vitamin A transported
A
retinol binding protein
9
Q
how does vitamin a transportation work
A
retinol binding protein picks up vitamin a from the liver and carries it in the blood
10
Q
what are some forms of retinoids
A
- retinol
- retinal
- retinoic acid
11
Q
what does retinol do
A
major storage form; important for reproduction
12
Q
what does retinal do
A
aldehyde form of vitamin A; vision
13
Q
what does retinoid acid do
A
acid form; hormones/growth
14
Q
retinoids are converted to __ in the intestine
A
retinol
15
Q
Foods from animals provide ___ readily digested and absorbed as retinol in the intestine
A
retinyl esters
16
Q
foods from __ provide carotenes
A
plants
17
Q
Beta carotene can be split to form retinol in the
A
intestine and liver
18
Q
__can be converted to other active forms of vitamin A
A
Retinol and Retinal
19
Q
Vitamin A is transported from the __ to the _
A
lymphatic system, liver
20
Q
__transports vitamin A from the liver in the blood
A
Retinol Binding Protein (RBP)
21
Q
Cells using vitamin A have
A
special protein receptors for it
22
Q
what are the primary functions of vitamin A
A
- Promote vision (retinal)
- Protein synthesis & cell differentiation
- Health of epithelial tissues and skin - Support reproduction (retinol)
- Acts as hormone regulating growth, cell differentiation, embryonic development (retinoic acid)
23
Q
how does vitamin A support vision health
A
- Maintains clear cornea
- Participates in conversion
of light energy into nerve impulses in the retina - Rhodopsin:
light sensitive pigment of the retina (contains retinal form of Vitamin A & protein opsin)
24
Q
what is cell differentiation
A
Process by which each type of cell develops to perform a specific function
25
what tissues are on the outside of the skin
skin-Epithelial tissue
26
what tissues are on the inside
Inside-Mucous membranes
| mucus-secreting cells; line the surfaces of body tissues
27
Vitamin A promotes differentiation of
epithelial cells & goblet cells (secrete & synthesize mucus)
28
what does mucus do
coats & protects epithelial cells from microorganisms and harmful substances
29
Retinol participates in __development
sperm
30
Vitamin A supports __ in pregnancy
normal fetal development
31
90% of vitamin A stored in the
liver
32
what vitamin inhibits replication of measles
A
33
what are some results of vitamin A deficiency
night blindness, blindness, keratinization
34
what are some symptoms of vitamin A deficiency
painful joints, impaired enamel formation, cracks in teeth
35
what causes night blindness
Retina does not receive enough retinal to regenerate the visual pigments bleached by light
36
what causes Xerophthalmia
lack of Vitamin A in the Cornea
37
what is a major cause of childhood blindness
lack of vitamin a in the cornea
38
define xerosis
Cornea becomes dry/hard due to inadequate mucus production
39
define keratomalacia
Softening of the cornea leading to irreversible blindness
40
how does vitamin A toxicity occur
when binding proteins are loaded
41
what kind of vitamin A cannot become toxic
beta carotene from foods
42
what are some vitamin A toxicity consequences
bone defects, birth defects
43
what does RAE stand for
retinol activity equivalents
44
what does IU stand for
International Units
45
what are some vitamin A food sources
dark leafy greens, yellow or orange fruits and vegetables, liver; 1 oz of beef liver provides more than 3Xs the RDA for Vitamin A
46
can the body synthesize vitamin D from sunlight
yes
47
is vitamin D a hormone
yes
48
what are the two forms of vitamin D
D2 ergocalciferol from plant foods and D3 cholecalciferol from animal foods and skin synthesis from 7-dehydrocholesterol
49
is vitamin D essential
no
50
vitamin d needs what organs for synthesis and activation
liver and kidneys
51
what is the active form of vitamin D and what activates it
calciferol, the kidneys and liver need to process it
52
what re the roles of vitamin D
```
Bone Growth
1. Maintenance of blood calcium and phosphorus levels
2. Assists in absorption of calcium and phosphorus from GI tract
3. If diet insufficient, vitamin D causes
-Reabsorption in kidneys
-Mobilization from bones into blood
Other roles in cells in:
-Brain & nervous system
-Reproductive organs
-Muscles and cartilage
-Pancreas
-Skin
-Immune system
```
53
how much fo the population is vitamin d deficient
10%
54
what are some diseases a result of vitamin D
1. Rickets
2. Osteomalacia
3. Osteoporosis
55
what are some signs and symptoms of rickets
bowed legs and beaded ribs
56
who is at risk of vitamin D deficiency
1. Elderly
2. Dark skinned
3. Breastfed infants without supplementation
- Supplement with 400 IU/day
5. Lack of sunlight
6. Living above 40ᵒ latitude in northern hemisphere (or below 40ᵒ latitude in southern hemisphere)
7. Not using fortified milk
57
what are the results of Vitamin D toxicity
1. Raises concentration of blood calcium
- Excess precipitates into soft tissues, forming stones
- Kidneys stones
2. Calcifies/hardens blood vessels
3. Dangerous especially to brain, heart & lungs- can cause death
58
what are some food sources of Vitamin D
1. Fortified milk
2. Fortified margarine
3. Fish canned with bones
4. 2 cups fortified milk daily
5. Egg yolks/oily fish (salmon, sardines, mackerel)
59
Sunscreens with SPF > __prevent vitamin D synthesis
8
60
do lighter or darker people require more sun exposer
darker
61
what is the general term for several related compounds to vitamin E
tocopherol
62
what is the active vitamin E compound in the human body
alpha-tocopherol
63
the RDA for vitamin E is based on __ only
alpha-tocopherol
64
what destroys vitamin E
heat and oxidation
65
what do antioxidants do
1. Stops the chain reaction of free radicals producing more free radicals
2. Prevents the oxidation of PUFAs
3. Protects other lipids and related compounds
4. Reduces the risk of heart disease by protecting LDL against oxidation and reducing inflammation
66
are vitamin E deficiencies rare
yes
67
Vitamin E deficiencies are usually associated with diseases that result in
fat malabsorption
68
what are some conditions that can result from vitamin E deficiency
1. erythrocyte hemolysis in premature infants
2. Hemolytic anemia- condition of too few RBCs as a result of erythrocyte hemolysis.
3. Neuromuscular dysfunction
involving spinal cord and retina of the eye
Loss of muscle coordination and reflexes and impaired vision and speech
69
what are some conditions that respond to vitamin E supplementation
1. Fibrocystic breast disease
2. Lumps in breasts
3. Intermittent claudication
Severe calf pain that is caused by inadequate blood supply
70
what are some results of vitamin E toxicity
1. Rare- liver regulates
2. Interference with blood clotting of vitamin K
3. Enhance the effects of anti-clotting drugs causing hemorrhage
71
what are some food sources for vitamin E
1. Polyunsaturated plant oils (Vegetable oils)
2. Margarine
3. Salad dressings
4. Dark, leafy greens
5. Wheat germ
6. Liver
7. Egg yolk
8. Nuts/seeds
72
is vitamin K essential
no, because it is made in your gut and meets about 50% of your needs
73
__ is part of the clotting process
prothrombin
74
what are some of the purposes of vitamin K
blood clotting, essential in prothrombin, metabolism of bone proteins
75
what kind of deficiency is more common for vitamin K
secondary, fat malabsorption
76
what can disrupt vitamin K synthesis
antibiotics and anticoagulant drugs
77
newborns require what kind of vitamin injection
K
78
is there an upper limit for vitamin K
no
79
what are some food sources for vitamin K
1. Liver
2. Leafy greens
3. Cabbage family
Smaller amounts in
-Milk
-Meats
-Eggs
-Cereals
-Fruits
-Vegetables
