Vitamins

Question 1

Vitamin B1 (thiamin) functions

Answer 1

oxidative decarboxylation reactions.
Need to have a molecule that can accept CO2 to pull it off a molecule when doing this reactions.
Transketolase reactions - hexose monophosphate shunt

Question 2

What animal needs dietary thiamin?

Answer 2

all animals, cats need 3x more than dogs

Question 3

Thiamin B deficiency

Answer 3

presents as weakness, neuropathy, and/or CNS disorders - beriberi (primates), polioencephalomalacia (cats/ruminants) - fatal if untreated
Excessive (toxic) thiamins is hard to achieve unintentionally

Question 4

Vitamin B2 (riboflavin) - energy
component of…
main function?
what animals need this?

Answer 4

energy (redox/respirator).

Main functions - component of FAD and FMN - central to cellular respiration. All animals need this.

Question 5

Vitamin B2 deficiency presents as..

Answer 5

non-specific symptoms (mucus membrane inflammation, alopecia, dermatitis, anemia) - rarely fatal.
Excessive to achieve unintentionally

Question 6

Vitamin B3 (niacin)

Answer 6

component of NAD+ and NADP - central to cellular respiration

Question 7

Vitamin B3 dietary needs
what can it be synthesized form?
intake of what is required?
what deficinecy leads to niacin synthesis?

Answer 7

Niacin can be synthesized in the body from nicotinamide or tryptophan, sufficient intake of tryptophan/nicotinaminde/niacin is required), B6 deficiency or excess leucine can inhibit TRp- niacin synthesis

Question 8

Deficiency of niacin results in

Answer 8

weakness and loss of appetite and in sever cases - dermatitis, diarrhea, and dementia. Toxic is hard to achieve.

Question 9

Vitamin B5 (pantothenic acid) functions
components of what compounds?

Answer 9

component of coenzyme A, component of phosphopantetheine

Question 10

Vitamin B5 is a dietary necessity for what animals?

Answer 10

growing animals (especially chicks)

Question 11

Deficiency for vitamin B5

Answer 11

deficiency is rare, usually secondary to general malnutrition, toxic is hard to achieve

Question 12

Vitamin B6 (pyridoxine) - energy
functions

Answer 12

energy (glycogen)
functions - binds to hemoglobin, cofactor for hundreds of reactions including gluconeogenesis, glycolysis, AA metabolism, etc. glycogen phosphorylase accounts for greater than 70% of B6

Question 13

Vitamin B6 necessary for

Answer 13

all animals

Question 14

Vitamin B6 deficiency

Answer 14

Deficiency is rare but may present as hyper irritability, seizures, and oral inflammation

Question 15

Vitamin B6 dietary necessary

Answer 15

all animals

Question 16

Vitamin B6 toxicity

Answer 16

excessive may lead to neuropathy and CNS confusion

Question 17

Vitamin B7 (Biotin)
Main functions
Necessary for..

Answer 17

Energy (carboxylation)
carboxylation reactions. anything with carboxylase
all animals

Question 18

Vitamin B7 deficiency and toxicity

Answer 18

Deficiency is rare and usually caused by deficient utilization, not diet - presents as dermatitis, alopecia, weakness.
Toxicity hard to achieve

Question 19

Vitamin B9 (folic acid)
Functions:
What does it create?
What action does it help?
necessary for...

Answer 19

Hematopoiesis (methylation). functions - biosynthesis of purines/pyrimidines (needed by rapidly dividing cells), methionine synthesis (indirectly through cobalamin), neural tube closer, necessary for all animals

Question 20

Vitamin B9 deficiency

Answer 20

usually presents as anemia due to impaired hematopoiesis or abnormal growth in juveniles, extreme deficiency can lead to death

Question 21

What to sulfa drugs do?

Answer 21

act to inhibit folate synthesis in bacteria

Question 22

Vitamin B12 (cobalamin)
functions - what does it synthesize and convert?
What animals is it necessary for?

Answer 22

Methionine synthesis, purine/pyrimidine synthesis (indirectly through folateA), conversion of propionate to succinyl-coA
Necessary for non-ruminants

Question 23

Vitamin B12 deficiency

Answer 23

rare, caused by diet or deficiency in absorption, presents as pernicious anemia. Cattle can have deficiency when fed cobalt deficient feed.

Question 24

Vitamin C (ascorbic acid)
Functions
what does it reduce?

Answer 24

soluble antioxidant, hydroxylation reactions of; lysine/hydroxyproline for collage, dopamine to norepinephrine, of cholesterol toward bile acids. Reduces Fe3+ to Fe2+ in intestine for iron absorption.

Question 25

Vitamin C dietary necessity for..

Answer 25

most animals can synthesize from glucose. Primates, fish, songbirds, flying mammals, or guinea pig need it.

Question 26

Vitamin C deficiency and excess amount..

Answer 26

deficiency presents as immunosuppression or connective tissue disorders.
Excessive vitamin C can lead to kidney stones or iron overload.

Question 27

Vitamin E

functions and dietary necessity, how is it packaged, necessity depends on intake of what?

Answer 27

Lipid antioxidant
Necessity for - all animals, varies based on unsaturated fatty acid intake, packaged in chylomicrons/lipoproteins in blood

Question 28

Vitamin E deficiency

toxicity can have..

Answer 28

presents as erythrocyte fragility, nerve and muscle disorders due to calcium influx into cells, may lead to sudden death
Toxicity can have anti-coagulative effect

Question 29

Vitamin A function

Dietary necessity?

Answer 29

vision - photosensitive. vision (rhodopsin), growth/differentiation factor (similar to steroid hormones).

Necessary for all animals, bound retinol binding protein or albumin in blood

Question 30

Vitamin A deficiency and toxicity

Answer 30

deficiency usually presents as visual disorder, cornification of mucosal epithelium, or infertility
Excess vitamin A occurs after retinal binding proteins have been saturated, leads to liver hypertrophy, skin desquamation, and bone demineralization

Question 31

Vitamin D

functions, activated where, in response to what?

Answer 31

Calcium/phosphate regulation

functions - calcium, magnesium absorption (intestine, steroid hormone) and activated at the kidney in response to PTH

Question 32

Vitamin D necessary for…

Answer 32

Carnivores (mammals can synthesize it from cholesterol using US radiation in the skin, insufficient amounts are produced by carnivores). bound to vitamin D binding protein in the blood

Question 33

Vitamin D deficiency

Answer 33

presents as abnormal bone mineralization and hypocalcemia. Excess causes hypercalcemia/hyperphosphatemia/ kidney stones

Question 34

Vitamin K functions and dietary necessity and necessary for..

Answer 34

coagulation
functions - carboxylation, maturation of clotting factors, bone metabolism.
necessity for all animals, easily accessible and ruminant microbes synthesize sufficient amounts, packaged as chylomicrons/lipoproteins in blood

Question 35

Vitamin K deficiency and excess…

Answer 35

deficiency presents as clotting disorders, severe deficiency can lead to death. excess is rare but may cause gastrointestinal disorders and anemia

Question 36

Clotting

Answer 36

Cascade of proenzymes that get activated to active enzymes (zymogens).
Long chains of proenzymes or zymogens.
When fibrin is active it is cross linked fibrin clot.
If we cant get thrombin and fibrin we cant get a clot.

Question 37

Vitamin K and clotting factors

Answer 37

We have to mature the coagulation factor and then cleave it to its active form which are maturation and cleavage (arrows).

There will be glutamate residues on the proteins which have on COOH, need these factors to be sensitive to calcium. Needs two COO- to complex the calcium. Im confused.

Question 38

Vitamin K and Warfarin

Answer 38

Vitamin K carboxylates the reaction. Gives up the COOH so it gets donated on the right side. Vitamin K is needed because it’s a cofactor. We can efficiently recycle vitamin K. Need clotting factors to be sensitive to calcium.
If we block the two left pathways we will make clotting factors but will run out of the quinol form so the clotting factors will drop.
Build up epoxide and run out of quinol.

Question 39

3 y/o rat terrier is brought in with coughing, shortness of breath, weakness, epistaxis. Examination shows pale gums, general hemorrhage/bruising
Follow up question?

Answer 39

Do you use rat bait? Older rat baits are vitamin K antagonists. Which means it wont allow vitamin K to do its job, important in clotting
Have you or one of your neighbors used rat bait poisons recently?
Owner reports that there have been problems with rats in out buildings and rat bait was placed three days ago.

Question 40

3 y/o rat terrier is brought in with coughing, shortness of breath, weakness, epistaxis. Examination shows pale gums, general hemorrhage/bruising
Diagnosis and Treatment

Answer 40

diagnosis -Anticoagulant poisoning. Can be verified with a prothrombin time test
Treatment -Blood to replace loss due to hemorrhage and to give immediate clotting factors. Oral or subcutaneous vitamin k for 3-4 weeks.
After treatment ends, verify that prothrombin time has returned to normal.