Vitamin A

Question 1

Is Vitamin A a water soluble or fat soluble vitamin?

Answer 1

It is a fat soluble vitamin

Question 2

How many forms of vitamin A are there?

Answer 2

There are two forms

Question 3

What are the two forms of vitamin A called?

Answer 3

Retinol

Beta-carotene

Question 4

What is retinol?

Answer 4

It is pure vitamin A

Question 5

Is retinol easy or difficult to absorb?

Answer 5

It is easy to absorb

Question 6

Where is retinol stored in the body?

Answer 6

The liver

Question 7

What is beta-carotene?

Answer 7

It is pro-vitamin A

Question 8

Is beta-carotene easy or difficult to absorb?

Answer 8

It is difficult to absorb

Question 9

Why is beta-carotene difficult to absorb?

Answer 9

It has to be converted into retinol in the lining of the intestine

Question 10

List the properties of retinol

5

Answer 10

A yellow, fat-soluble alcohol

Insoluble in water

Soluble in organic solvents e.g. acetone

Heat stable, but affected by prolonged high temperatures

Destroyed by oxygen

Question 11

List the properties of beta-carotene

6

Answer 11

A yellow or orange fat-soluble oil

Insoluble in water

Soluble in fat solvents, e.g. alcohol

Heat stable, but affected by prolonged high temperatures

Unaffected by oxygen

Powerful antioxidant

Question 12

What effect do antioxidants have on the body?

Answer 12

They have the ability to counteract the damaging effects of free radicals

Question 13

List the sources of retinol

8

Answer 13

Fish liver oils 
Milk 
Eggs 
Butter 
Offal 
Cheese
Margarine 
Oily fish

Question 14

List the sources of beta-carotene

6

Answer 14

Carrots 
Tomatoes 
Red peppers 
Leafy green vegetables 
Apricots 
Sweet potatoes

Question 15

Retinol usually comes from what type of food?

Answer 15

Animal sources

Question 16

Beta-carotene usually comes from what type of food?

Answer 16

Carotenoids which are yellow, green and orange fruit and vegetables

Question 17

List the functions of vitamin A

5

Answer 17

Manufactures rhodopsin in the retina

Helps maintain healthy skin and mucous membranes

Healthy skin and hair

Aids growth and development

Beta-carotene acts as a powerful antioxidant

Question 18

Vitamin A aids in the manufacture of rhodopsin in the retina, describe this function

Answer 18

Vitamin A is required to manufacture the pigment rhodopsin found in the retina which helps the eye adapt to dim light

Question 19

Vitamin A helps maintain healthy skin and mucous membranes, describe this function.

Answer 19

Vitamin A helps maintain healthy skin and the mucous membranes of the body such as the eyes, nose and throat which prevents infection

Question 20

List the effects of a deficiency of vitamin A

5

Answer 20

Night blindness

Follicular hyperkeratosis

Xeropthalmia

Stunted or delayed growth in children

Damage to cells/cancer

Question 21

A deficiency of vitamin A results in night blindness, describe this deficiency

Answer 21

One with night blindness will struggle to see in dim light due to a lack of rhodopsin

Question 22

A deficiency of vitamin A results in follicular hyperkeratosis, describe this deficiency

Answer 22

This is a condition that results in rough, dry skin and inflamed hair follicles

Question 23

A deficiency of vitamin A results in xeropthalmia, describe this deficiency
(2)

Answer 23

This occurs on the surface of the eye due to a lack of mucous
This causes eyes to dry out and become infected with bacteria and can eventually lead to blindness

Question 24

A deficiency of vitamin A results in damage to cells and an increased risk of cancer, describe this deficiency

Answer 24

Damage to cells by free radicals increases the risk of some cancers, coronary heart diseases and strokes

Question 25

What is the RI for children?

Answer 25

400-500 micrograms

Question 26

What is the RI for adolescents and adults?

Answer 26

600-700 micrograms

Question 27

What is the RI for pregnant women?

Answer 27

700 micrograms

Question 28

What is the RI for lactating women?

Answer 28

950 micrograms