Chapter 8 (pt.2): Vitamins (Hill) Flashcards Preview

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Flashcards in Chapter 8 (pt.2): Vitamins (Hill) Deck (63):
0

Vitamin A and E - required by what animals and have what effects on the body?

required by all animals

may have beneficial effects on immunity

1

in what way do vitamins A and D act like hormones?

regulating DNA transcription

2

deficiency of fat soluble vitamins accompany what condition?

fat malabsorption

3

Source of Vitamin A and carotenoids

plants do not contain vitamin A (retinol) but they do contain carotenoids which can be split in the body to form retinol except in cats and they therefore must be given retinol in the diet.

hay and corn - contain carotene

cod liver oil - retinol

4

function of Vitamin A (retinol) and carotenoids

- light pigment rhodopsin aka night vision
- affects DNA transcription by:
-- **promoting skin and mucosal differentiation and proliferation. carotenoids have been used at high doses to treat solar dermatitis and squamous cell carcinoma in dogs**
- increased immunity
- **carotenoids act as antioxidants**

5

Vitamin A (retinol) and carotenoids: deficiency

- night blindness
- **common in seed-eating birds: cutaneous abscesses
- poor heat tolerance, emaciation, weakness, mastitis, etc

6

Vitamin A (retinol) and carotenoid: toxicity

*cervical spondylosis in cats fed exclusively liver*

*and in anteater pet foods*

*polar bear liver contains very high concentrations*

7

Vitamin D sources

*dogs and cats cannot synthesize in skin so must have external sources*
- formed in skin by action of sunlight
- hays, fish liver oils, irradiated yeast

8

what species of animal cannot use Vitamin D2 and must use Vitamin D3? ***

***new world monkeys and poultry - must Vitamin D3 only!

9

Vitamin D function

hormone which regulates Ca and P absorption from intestine and resorption from bone and Ca absorption in kidney

10

Vitamin D deficiency

***Rickets seen in animals deprived of sunlight - especially reptiles
** chronic renal failure

11

Vitamin D toxicity

excess supplementation in pet foods or owners

rodenticide poisoning

12

Vitamin E sources

vegetable oils, wheat germ

13

Vitamin E function

Vitamin E (tocopherol) acts as an antioxiant in pet food but is oxidized over time. tocopherol acetate in pet food is converted to Vitamin E in the body where its used as an antioxidant but has no oxidant activity in food before transformation.

- immune stimulant

14

Vitamin E deficiency

- myopathy, poor reproduction, mastitis
** common in fish-eating mammals**
- ** possibly responsible for steatitis in cats

15

Vitamin E toxicity

high doses interfere with Vitamin K metabolism and platelet function

16

therapeutic uses of Vitamin E

is used for any disease where oxidation is part of pathogenesis like **reperfusion injury**

17

Vitamin K sources

intestinal bacteria
green plants

18

Vitamin K function

cofactor in synthesis of clotting factors: 2, 7, 9 and 10

19

Vitamin K deficiency

symptom is hemmorhage as in **Warfarin poisoning**
also seen in **fat malabsorptoin due to bile duct obstruction** and fatty liver disease

20

what water soluble vitamin is produced in the rumen not an essential nutrient in cattle?

vitamin B

21

what water soluble vitamin is easily destroyed by heat so "overage" is added to pet food diets to accomodate losses?

vitamin B

22

Vitamin C sources***

*** synthesized by most species except primates, guinea pigs, some bats, some birds (Bulbuls), fish and invertebrates ***

23

Vitamin C function

antioxidant
**hydroxylation of proline and lysine in collagen formation***
fibroblast and osteoblast function
important for immunity and carnitine synthesis

24

Vitamin C deficiency

- "scurvy" - loose teeth, poor wound healing, ruptured capillaries, etc.
- dogs and cats synthesize ascorbic acid in liver
- some say supplementation is needed during times of stress

25

Vitamin B1 (thiamin) sources

yeast

26

Vitami B1 (thiamin) function

as the coenzyme for enzymes involved in energy metabolism like : acetyl CoA and succinyl CoA

27

***Vitamin B1 (thiamin) deficiency***

*** bracken, fish and heart and spleen can contain thiaminases so can induce deficiency in fish eating mammals, birds of prey fed chicks and horses eating bracken****

***seen in calves, sheep, greyhounds and cats***

***heart failure can be induced by glucose infusion in deficient humans.

***signs: ataxia, impaired righting reflexes, impaired vestibulo-ocular reflexes, poorly responsive pupils, ventroflexion of neck, circling, cardiac arrhythmias. pathology is cerbro cortical necrosis***

28

Vitamin B2 (Riboflavin) sources

yeast, milk and alfalfa meal

29

Vitamin B2 Riboflavin: function

act as coenzymes for FAD and FMN in oxidation/reduction actions

30

Vitamin B2: riboflavin - deficiency *

poor growth,

**angular stomatitis in humans**

31

Vitamin B3 (niacin) : sources

corn, wheat are poor sources

yeast, wheat bran and sunflower and peanut meals are rich sources

32

vitamin B3 (niacin): function

act as coenzymes for NAD and NAP so involved in all energy reactions
- used to treat hyperlipidemia in humans and in ***hypocholesterolemic in dogs***

33

Vitamin B3 (niacin): deficiency

**dogs fed un-supplemented diets develop pellagra-like lesions "black tongue"**

signs: inappetance, poor growth, diarrhea, dermatitis

34

**Vitamin B3 (niacin) toxicity**

***profound vasodilation***

35

Vitamin B5 (Pantothenic Acid): sources

yeast, milk, molasses

36

Vitamin B5 (Pantothenic Acid) : function

part of coenzyme A

37

vitamin B5 (Pantothenic Acid): deficiency

rare

38

Vitamin B6 (Pyridoxine) sources

yeast, wheat gram, molasses

39

vitamin B6 (Pyridoxine): function

acts as a coenzyme in amino acid metabolism for ALT and AST

40

Vitamin B6 (pyridoxine): deficiency

poor growth and inappetence, dermatitis, and neurological signs

41

Vitamin B12 (cobalamin): sources

microorganisms in feces, yeast and animal byproducts

42

Vitamin B12 (cobalamin): function

acts as coenzyme for succinyl CoA and methionine

formation of nucleic acids and myelin

43

Vitamin B12 (Cobalamin): absorption

dependent on intrinsic factor from the stomach and pancreas in dogs and just the pancreas in cats

**absorption is carrier mediated in the ileum***

44

Vitamin B12 (Cobalamin): deficiency

inappetance, poor growth and neuropathies

mild normocytic anemia in giant Schnauzers

***idiopathic malabsorption in Giant schnauzers**

45

****what conditions are commonly associated with a mild deficiency in Vitamin B12 (Cobalamin)****

*****
- small intestinal disease affecting the ileum
- bacterial overgrowth (bacteria compete for B12)
- pancreatic insufficiency in cats (absence of IF)
- unsupplemented home-cooked diets

****************

46

Folate : sources

bacteria in small intestine synthesize folate so slight increase in blood levels in dogs with small intestinal bacterial overgrowth

47

folate: function

precursor of tetrahydrofolate

48

***folate: absorption***

*** in proximal small intestine***

49

***folate: metabolism***

*** bacteria absorb paraaminobenzoid acid (PABA) which is converted to folate and then converted to tetrahydrofolate (folacin) by the enzyme tetrahydrofolate reductase (THFR).

sulfa antibiotics inhibit the first step: trimethoprim and pyrimethamine the second (THFR inhibitors). the cancer drug, methotrexate also inhibits THFR.

50

folate: defieincy

signs: slow growth, low dividing cells --> anemia, low WBC count

** decreased blood levels in dogs with proximal small intestinal disease**

**deficiency can be precipitated by overdose of trimethoprim sulfa antibiotics or methotrexate: use folate to treat sulfa toxicosis and folacin to treat trimethoprim/methotrexate toxicosis**

**horses not on pasture may be deficient in folate**

51

Biotin sources

yeast, rice bran

52

biotin: function

coenzyme of carboxylases involved in fat and carb metabolism:

pyruvate --> oxaloacetate
acetyl CoA --> malonyl CoA
priopionyl CoA --> methylmalonyl coA

53

Biotin: deficiency

cats fed experimental diets containing raw egg whites were deficient in biotin

signs include: poor growth, poor haircoat, dermatitis

54

Choline: sources

yeast

poor source: grains

55

choline: function

methyl donor in phosopholipid metabolism and part of acetylcholine

56

***choline: deficiency***

*** methionine can act as an alternative methyl donor so choline is probably not required if sufficient methionine is provided above amino acid requirements***

signs: poor growth and hepatic lipidosis

**has been recommended as part of treatment for hepatic lipidosis in cats***

57

Vitamin like molecule: inositol

sources

biosyntehsis
free in animal tissue
as phytate plant tissue

58

vitamin like molecule: Inositol

function

second messenger in cells
phospholipids

59

vitamin-like molecule: Inositol

minimum requirement in what species?

in cats because experimental diets all contained some inositol

60

Inositol supplementation

recommended for fatty liver in cats

decreased nerve conduction in diabetic rats

61

vitamin-like molecule: pyrroloquinalone quinone (PQQ, 'Q10'):
sources

synthesis by cells and ubiquitous in diet

62

PQQ, 'Q10'
function

required for grwoth in rodents, antioxidant, may reduce the incidence of athersclerosis in humans