Brainscape's Knowledge GenomeTM

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


See full index

Nutrient Metabolism > Vitamin D > Flashcards

Vitamin D Flashcards

1
Q

What are the factors affecting Vit D synthesis

A

Melanin, UVB, Age, UVB shielding

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

Where does Vit D synthesis begin

A

The skin

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

What “pushes start button” in Vit D synthesis

A

The sun

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

What molecule begins Vit D synthesis in skin

A

Cholesterol

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

Acetyl CoA and Cholesterol create which form of Vit D in the skin

A

proVitD3 - 7-Dehydrocholesterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

ProVitD3 + UVB =

A

PreVitD3

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

PreVitD3 + Skin Temp =

A

Vitamin D3

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

What is the animal source of VitD3

A

Cholecalciferol

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

What is the plant source of Vitamin D

A

Ergocalciferol - VitD2

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

Why is VitD2 “not as good” as VitD3

A

Does not stay in the blood as long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

VitD3–>Circulation–>Liver–>25-OHase =

A

25(OH)D3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What enzyme converts VitD3 to 25(OH)D3?

A

25-OHase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What converts ProVitD3 to PreVitD3

A

UVB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is another name for ProVitD3

A

7-Dehydrocholesterol

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

What converts PreVitD3 to Vitamin D3

A

Skin temperature

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

25(OH)D3 –>1-OHase in kidney =

A

1,25(OH)2D3 - Calcitriol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the active form of Vitamin D

A

Calcitriol - 1,25(OH)2D3

18
Q

What enzyme converts 25(OH)D3 to Calcitriol

A

1-OHase

19
Q

Where does 1-OHase convert 25(OH)D3 to Calcitriol

A

Kidneys

20
Q

How is Vitamin D status measured (form)

A

25(OH)D3

21
Q

When is it best to measure Vitamin D status

A

End of winter (storage in adipose used up)

22
Q

Where is Vitamin D stored

A

Adipose tissue

23
Q

When will Vitamin D status be highest

A

August/September

24
Q

What can cause Vitamin D deficiency (organs)

A

Liver/kidney failure

25
Q

What is a treatment for Vitamin D deficiency (organ failure)

A

Calcitriol Rx (active form)

26
Q

What is a function of calcitriol in the kidneys

A

Increase calcium resorption (less excreted)

27
Q

Why don’t VitD and Calcium need to be taken at the same time

A

VitD still has to be activated, first to Calcitriol, then process to form Calbindin protein

28
Q

How is VitD absorbed

A

Follows the route of lipids

29
Q

How is VitD excreted

A

> 70% feces, urine

30
Q

What is the UL for VitD

A

4,000IU

31
Q

What is caused by VitD deficiency in children

A

Rickets

32
Q

What is caused by VitD deficiency in adults

A

Osteomalacia

33
Q

What are the symptoms of rickets

A

Bones don’t mineralize, bone still trying to grow, legs show symptoms because support body weight, growth retardation

34
Q

What are the symptoms of Osteomalacia

A

Poor bone mineralization; bones translucent

35
Q

What are food sources of VitD

A

Egg yolk, beef, tuna cheese, mushrooms, tofu, fortified milk

36
Q

What is the RDA for VitD 1-70years

A

600IU

37
Q

What is the RDA for VitD 70+years

A

800IU

38
Q

What is the Natl Osteoporosis Found recommendation for VitD 50+years

A

800-1000IU

39
Q

Why does sun over-exposure not result in VitD toxicity

A

too much UVB will destroy preVitD3

40
Q

What is VitD (Calcitriol) “claim to fame”

A

Calcium Homeostasis: Calcium absorption in enterocyte; Calcium resorption in kidney; Calcitriol, 24R,25(OH)2D3 & bone

41
Q

What are functions of VitD other than Calcium homeostasis

A

Cell differentiation, proliferation and growth-May prevent abnormal cell growth(cancer); Blood pressure, insulin secretion, autoimmune disorders; Blood volume control

42
Q

What is a symptom of VitD deficiency in children other than Rickets

A

Seizures

Nutrient Metabolism (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions