Vitamins

Question 1

What are vitamins?

Answer 1

Organic compounds required in very small quantities for normal body function.

Question 2

What are the two classes?

Answer 2

Fat soluble and water soluble

Question 3

What are the fat soluble minerals?

Answer 3

A, D, E & K

Question 4

Name the chemical names for vitamins A, D, E and K.

Answer 4

A - retinol
D - calciferols
E - tocopherols
K - quinones

Question 5

What are the water soluble vitamins?

Answer 5

B complex and C

Question 6

What is the chemical name for vitamin C?

Answer 6

Ascorbic acid

Question 7

Name the 12 B-complex vitamins.

Answer 7

B1 - Thiamin
B2 - Riboflavin
B3 -Nicotinic Acid / Niacin
B5 - Pantothenic Acid
B6 - Pyridoxine
B7 * - Biotin
B9 - Folic Acid
B12 - Cyanocobalamin

Question 8

What are provitamins?

Answer 8

Precursors - compounds that act as vitamins only after undergoing chemical change to active forms in the body.

Question 9

How are many vitamins destroyed?

Answer 9

Oxidation and how food is processed/stored/cooked can have a major influence on level of vitamins it contains.

Question 10

Define avitaminosis.

Answer 10

Total absence (rare)

Question 11

Define hypovitaminosis.

Answer 11

Partial lack (common)

Question 12

Define hypervitaminosis.

Answer 12

Excessive provision (only occurs with a few vitamins)

Question 13

Describe the metabolic functions of retinol.

Answer 13

1. Formation & integrity of epithelia & mucous membranes
2. Retinal function –> combines with opsin to form rhodopsin needed for night vision
3. Bone growth
4. Immune function

Question 14

What is a precursor to vitamin A and how is it converted?

Answer 14

β carotene - converted to retinol during absorption through the gut wall.

Question 15

Where is retinol stored and what does this mean for animals diet?

Answer 15

Stored in the liver so animals do not require a daily supply.

Question 16

What are good sources of retinol?

Answer 16

Liver (cod liver oil), egg yolk and milk fat

Question 17

What is a good source of β carotene?

Answer 17

Plants (grass)

Question 18

Name a problem with cattle with a retinol deficiency (mild and prolonged).

Answer 18

Mild - rough scaly skin
Prolonged deficiency - ‘night blindness’, lachrymation, corneal opacity.

Question 19

How common is retinol deficiency in cattle and why?

Answer 19

Rare in adults as carotenoids acquired at pasture replenish hepatic stores of Vitamin A –> able to provide adequate retinol cover over winter periods.

Question 20

List the symptoms of hypervitaminosis in dogs and cats.

Answer 20

• Abnormal bone deposition
• Lameness
• Vertebral spondylosis
• Gingivitis
• Weight loss
• Poor coat

Question 21

How do you obtain vitamin D?

Answer 21

1. Sunlight on skin!!!
2. Fish (oily)
3. Egg yolk
4. Hay (sun-dried roughages)
5. Colostrum

Question 22

Name the vitamin D metabolic functions.

Answer 22

It helps regulate the amount of calcium and phosphorus in the body - promotes Ca2+ absorption from digesta in the gut lumen.

Question 23

Name problems with vitamin D deficiencies.

Answer 23

1. Rickets - soft weak deformed bones in young growing animals
2. Osteomalacia in adults (weak bones)
3. Poor egg sell quality and weak bones in poultry

Question 24

What are the sources of vitamin E?

Answer 24

Green fodder (grass, green vegetables) and cereals (but decreases rapidly during storage).

Question 25

Describe the metabolic function of Vitamin E.

Answer 25

1. Biological antioxidant - acts in combo with the selenium containing enzyme, glutathione peroxidase, to protect cells from oxidative damage caused by free radicals. 2. Important for normal reproductive function, muscular function & capillary integrity.

Question 26

Name the problems with vitamin E deficiency.

Answer 26

- Nutritional myopathy - Cardiac disease - Brain damage - Lameness & muscle stiffness

Question 27

Name the sources of vitamin K.

Answer 27

1. Green, leafy materials 2. Egg yolk, liver and fish 3. Gut bacteria synthesise

Question 28

Describe the metabolic functions of vitamin K.

Answer 28

1. Essential for the normal clotting of blood 2. Bone and kidney function

Question 29

What are the signs of vitamin K deficiency in ruminants, horses, pigs and chicks?

Answer 29

Unlikely to occur in cattle, horses and pigs. Chicks - anaemia & delayed clotting of blood

Question 30

Name the source of B complex vitamins in ruminants.

Answer 30

Rumen bacteria can synthesis e B vitamins in sufficient quantities.

Question 31

What is the metabolic function of B complex vitamins?

Answer 31

Pathways of cellular respiration and energy transfer; co-enzymes.

Question 32

Name the sources of B complex vitamins.

Answer 32

Liver, yeasts, green foods, cereals, milk

Question 33

Describe the metabolic function of thiamine (B1) and the signs of deficiency.

Answer 33

Initiation & propagation of nerve impulses - paralysis, blindness, progressive dysfunction of the NS, loss of appetite.

Question 34

What are the sources of vitamin C?

Answer 34

Citrus fruits, green leafy vegetables, synthetic

Question 35

What are the metabolic functions of vitamin C?

Answer 35

- Normal collagen formation - Metabolic oxidation & reduction pathways - Iron transport - Antioxidant

Question 36

In what species is vitamin C necessary in diet?

Answer 36

Guinea pigs

Question 37

How do other species obtain vitamin C (not necessary in diet)?

Answer 37

Synthesise from glucose

Question 38

What are the signs of vitamin C deficiency?

Answer 38

Scurvy - muscle and joint pain, lethargy, the appearance of red dots on the skin, bleeding and swelling of the gums, diarrhoea, weight loss, rough hair coat, reduced immune function.