Fat soluble nutrients & some minerals

Question 0

What are the primary sources of Vitamin A?

Answer 0

mostly found in animal products such as;

• Liver
• Cheese
• Butter
• Fish
• Milk

Question 1

What is the other name for Vitamin A

Answer 1

Retinol

Question 2

What are Carotenoids?

Answer 2

they are a precursor to Retinol, and are synthesised by a wide variety of plants

Question 3

What are all the Carotenoids?

Answer 3

B-carotene
Lutein
Canthaxanthin
Lycopene

Question 4

What type of Carotenoid is found in Carrots, rockmelon, peas, spinach?

Answer 4

B-carotene, it has the greatest Vit A activity being 50%

Question 5

What type of Vitamin A is found in Broccoli, Beetroot, and Kiwi fruit?

Answer 5

Lutein

Question 6

What types of foods are Canthaxanthin found in and what vitamin is it a pre-cursor for?

Answer 6

it is found in red/orange plants, fish (trout, salmon), and seafood crustaceans. It is from Vitamin A, Retinol

Question 7

What pre-cursors are added to food as colour additives?

Answer 7

B-carotene and canthaxanthins

Question 8

What are the different form of Vitamin A?

Answer 8

• Retinol (the alcohol)
• Retinoic acid (oxidised active form)
• Retinal (active form)
• Retinyl ester (storage form in fatty tissue or liver)
• Provitamin A Carotenoids

Question 9

Explain the changes in forms from one form of Vitamin A to another?

Answer 9

Retinal is oxidised to Retinoic Acid
Retinal is reduced to Retinol
Retinyl Esters are hydrolysed into Retinol

Question 10

How is 2 Retinal formed?

Answer 10

betacarotene + 02

Question 11

What does LRAT stand for?

Answer 11

Lecithin Retinol Acyl-Transferase

Question 12

What does CRBP stand for?

Answer 12

Cellular Retinoid Binding Protein Vitamins

Question 13

Where does the Albumin Retinoic Acid Complex travel to?

Answer 13

the liver

Question 14

Where does the Chylomicron travel?

Answer 14

to the Lymph System

Question 15

What extra cellular tissues do Chylomicrons deliver retinyl eters and carotenoids to?

Answer 15

bone marrow, blood cells, spleen adipose tissue, muscle, lungs and kidneys.

Question 16

What happens to the retinyl esters and carotenoids that are not taken up by tissue?

Answer 16

they are delivered to the liver by chylomicron remnants

Question 17

What is the Retinol mobilisation from the liver to other target cells dependent on?

Answer 17

the synthesis and secretion of rentinol-binding protein (RBP) by the parenchymal cells

Question 18

What does Synthesis of RBP in the liver require?

Answer 18

zinc and protein

Question 19

How does the absorption of Vitamin A take place over the brush boarder?

Answer 19

Active transport via Micelle

Question 20

Which two proteins are required for Vitamin A metabolism in the cell?

Answer 20

Chylomicrons and Chylomicron remnants

Question 21

Inside the Enterocyte which Vitamin B is needed to form Retinol from B-Carotene?

Answer 21

NAD, Niacin, B3

Question 22

Name two substances that may enhance vitamin A absoption?

Answer 22

Vitamin E and lipoproteins (fats)

Question 23

Name two substances that may impair the absorption of Vitamin A?

Answer 23

Fibre and too much Vitamin E

Question 24

Where are excess Vitamin a stored?

Answer 24

fat cells

Question 25

B-Carotenoid & lycopene are transported via

Answer 25

mostly - lipoproteins | then - LDL's

Question 26

Lutein & Zeaxanthin are transported via

Answer 26

mostly HDL's | then LDL's

Question 27

What does CRABP's stand for and what are their functions?

Answer 27

Cellular retinoic acid binding protein, they produce small amounts of free retinoic acid within all cells

Question 28

What are the two forms of Vitamin D?

Answer 28

D2 - Ergocalciferol | D3 - Cholecalciferol

Question 29

What are the sources of Vit D?

Answer 29

main source from the skin via the sun, other animal sources such as liver, Beef, Veal, Dairy, Eggs, Butter and Fish.

Question 30

How is Vit D synthesized by the the skin?

Answer 30

Cholesterol forms 7-dehydrocholestrol (steroid), then with UV light exposure Previtamin D3 (precalciferol) is formed, which then forms Vit D3 (Cholecaliferol), which is then reabsorbed back into the blood stream via plasma transporters a2-globulins, then to D-binding protein (DBP)

Question 31

Via what other mechanism can Vit D be transported to tissues?

Answer 31

D-binding protein (DBP) Chylomicrons R B3 dependant transport from the liver to the blood

Question 32

How does phosphorous intake impair calcitriol production?

Answer 32

- low phosphorus levels increase Vit D production | - high phosphorus levels decrease Vit D production & increase calcium excretion in the urine

Question 33

What are the two main different form of vit E?

Answer 33

Tocopherols & Tocotriendols

Question 34

Vit E that is not used in periperal cells is stored where?

Answer 34

in the liver

Question 35

Once over the Basolateral boarder how is Vit E transported to the liver?

Answer 35

Chylomicron remnants

Question 36

How is Vit E mainly transported after leaving the liver?

Answer 36

via HDL and VLDL's

Question 37

What is Vit E's main function in these particles?

Answer 37

as a protein binder in the cell membrane

Question 38

Where does Vit E exist in cells?

Answer 38

the cell membrane

Question 39

Name 2 types of vitamin K, one exogenous and one endogenous type and from where are they found or produced?

Answer 39

Phylloquinone (K1) is an endogenous type, and it is found in plant products such as broccoli. Menadione (K3) is an exogenous type and it is found in synthetic supplements produced in a lab

Question 40

What is a known antagonist of vitamin K?

Answer 40

Warfarin

Question 41

How is vitamin K transported over the | basolateral boarder?

Answer 41

active transport via chyclomicrons

Question 42

For what reason is the calcium present in foods and supplements relatively insoluble?

Answer 42

because it needs to be attached to a sugar or acid for absorption, such a the HCL in the stomach

Question 43

Via which binding sites does calcium get up taken over the | brush boarder?

Answer 43

Calbindin or calcium Transporter 1

Question 44

Name three substances which may bind calcium to be | excreted in feaces?

Answer 44

fibre, phytate, fatty acids or oxalate

Question 45

List two factors which may increase the absorption of | calcium?

Answer 45

- low dietary intake - pregnancy, lactation - Oestrogen deficiency due to decreased calcitrol production

Question 46

List four factors which may inhibit calcium absorption?

Answer 46

- Caffeine - Fibre & phytates - high sodium intake - mag, zinc complete with ca for aborption - Oxalates in intestines - Parathyroid insufficiency - unabsorbed fatty acids - proton pump inhibitors

Question 47

What is the active form of Calcium?

Answer 47

Calcitriol which is converted by the kidneys