Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Nutrition > Fat Soluble Vitamins > Flashcards

Fat Soluble Vitamins Flashcards

1
Q

Retinal

A

important for vision
gets converted into 11-cis-retinal and then rhodopsin
beta-carotene (50%) converted into retinal in small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Retinol

A

required for reproduction, utilized in testes/ovaries

can be made from retinal or retinyl esters in the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

All trans retinoic acid

A

required for gene activation, growth, differentiation and maintenance of epithelial tissue (GI, lungs, cornea, e.g.)
made from retinol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Vitamin A absorption

A 
70-90% retinyl esters
20-50% beta-carotene 
(iron needed for beta-carotene monooxygenase)
increased by cooking/processing
decreased by fiber, esp pectin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Vitamin A target tissues

A 
70-75% to:
bone marrow
muscle
lungs 
kidneys
adipose (stores 15-20%)
the rest goes to the liver (stored as retinyl palmitate in stellate cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Vitamin A functions

A

vision - rhodopsin
gene transcription - regulates growth of epithelium, bones, teeth (all trans retinoic acid); reproductive health (retinol)
RBC production
immune function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Retinoic acid

A

GENE TRANSCRIPTION
regulates enzymes re:cell growth, differentiation, apoptosis
- incr gap jct protein connexin
- supports differentiation of keratinocytes, immune cells, and stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Vitamin A DRI

A

females - 700 mcg/2333 IU

males - 900 mcg/3000 IU

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Vitamin A testing

A

serum retinol

serum RBP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Vitamin A deficiency

A

primary = decr intake; secondary = lipid malabsorption

conjunctival xerosis (bitot's spots)
excess keratinization
incr susceptibility to infx
night blindness
delayed growth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Vitamin A toxicity

A 
> 25,000 IU/day
liver damage 
- hepatocyte hyperplasia and hypertrophy
- elevated liver enzymes
N/V, HA
bone/joint pain
incr risk of birth defects
SE - skin yellowing (carotenoids - no risk of toxicity)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Vitamin A food sources:

retinol/retinyl esters

A 
liver
butter
eggs
fortified dairy
fish - sardines, tuna, herring
fortified cereal grains
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Vitamin A food sources:

Beta-carotene

A 
dandelion greens
spinach
collard, kale
turnip greens
pumpkin
winter squash
sweet potato
carrot
raw cantaloupe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Vitamin D active form

A

calcitriol

1,25-dihydroxycholecalciferol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Vitamin D metabolism

A

7-dehydrocholesterol converted by UVB light to
cholecalciferol (D3) converted by liver to
25-hydroxycholecalciferol converted by kidneys to
1,25-dihydroxycholecalciferol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Vitamin D regulation

A

kidney hydroxylation regulated by:

  • PTH (incr vit d production in re:to decr calcium)
  • fibroblast-like growth factor 23 (decr vit d production)
  • negative feedback inhibition
17
Q

Vitamin D RDA

A

1-70 yo = 600 IU (15 mcg) harvard says 1000-2000 IU
> 70 = 800 IU (20 mcg)
UL = 4000 IU (100 mcg)

does not pass through breast milk
- 400 IU/day for infants

18
Q

Vitamin D food sources

A 
liver
egg yolk
fortified milk, margarine, butter, cereal
mushrooms
fatty fish - salmon, sardines, herring
19
Q

Vitamin D absorption

A

50% ingested = absorbed, mostly in distal SI

  • 40% then incorporated into micelles, transported via chylomicrons —-> adipose/muscle
  • 60% then transported via it D-binding protein —> liver
20
Q

Vitamin D functions

A

non-genomic - binds to membrane receptor to affect calcium uptake

genomic - binds to cellular receptor (VDR) in immune cells, prostate, colon, breast, skin, pancreas, adrenal glands, brain, muscle

21
Q

Vitamin D functions (2)

A 
calcium balance 
cell differentiation
gene transcription
immune system modulator
insulin secretion
blood pressure regulation (suppresses renin ---> decr angiotensin II)
22
Q

Vitamin D deficiency

A

rickets (children) - inadequate calcification

osteomalacia (adults) - soft deformed bones, pain, weakness

23
Q

Risks for vitamin D deficiency

A 
reduced UV availability and skin penetration
impaired skin synthesis (aging)
kidney disease
low dietary intake/absorption
tissue sequestering (obesity)
24
Q

Vitamin D excess/toxicity

A

elevated blood calcium —> calcification of soft tissue
to check status - serum 25-OH vitamin D
- up to 80-100 ng/mL appears to be safe

25
Q

Vitamin E RDA

A

15 mg/day
UL = 1000 mg

(1 IU = 0.66 mg of d-alpha-tocopherol and 0.45 mg of dl-alpha tocopherol))

26
Q

Vitamin E absorption

A
  • tocopherols = free in food, up to 80% absorbed

- tocotrienols = esterified and must be hydrolyzed,

27
Q

Vitamin E functions

A

antioxidant
stabilization of cell membranes (protects unsaturated FAs)
protects LDL from oxidation
{regenerated by ascorbic acid)

28
Q

Vitamin E deficiency

A

assess via serum vitamin E

29
Q

Vitamin E toxicity

A

rarely seen

possibly —> diarrhea, fatigue, double vision, muscle weakness

30
Q

Vitamin E food sources

A 
leafy greens
PUFA plant oils
almonds
sunflower seeds
wheat germ, whole grains
egg yolks
avocados
tomatoes
31
Q

Vitamin K forms

A

K1 = phylloquinone
- best food source = plants
K2 = menaquinone (active form in the body)
- low amt in food, most = converted from K1 by gut bacteria (bacteroides fragile, eubacterium, propionibacterium) and in vasculature

32
Q

Vitamin K2

A

15x more active than other forms
better absorbed, longer biological activity
= predominant form found in body tissues

33
Q

Vitamin K AI (adequate intake)

A 
females = 90 mcg/day
males = 120 mcg/day
34
Q

Vitamin K absorption

A 
phylloquinones = easily absorbed via micelles
menaquinones = passive diffusion in lower GI
delivered via chylomicrons to:
lungs
kidneys
bone marrow
adrenal glands
35
Q

Vitamin K functions

A
  • facilitates carboxylation with glutamate residues
  • – subsequent incr negative charge allows calcium to bind to proteins and activate (as seen in clotting factors, osteocalcin in bone, and matrix Gla protein in vasculature)
36
Q

Vitamin K functions (2)

A

blood clotting
bone health
- synthesis of osteocalcin; prevents bone loss
- integration of ca into bones
- prevents ca depot in vasculature and maintains elasticity

37
Q

Vitamin K excess

A

uncommon
no known toxicities
high doses can decr anti-clotting medication efficacy

38
Q

Vitamin K deficiency

A

reduced clotting time (easy bruising and bleeding)

osteoporosis

39
Q

Vitamin K food sources

A

leafy greens

brassicas

Nutrition (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions