Vitamins - Answers

Arlo Guthrie — Fri, 13 Feb 2009 12:21:05 GMT

Current Revision posted to Revision Guide For Student Nurses - Part 1 by Arlo Guthrie on 2/13/2009 12:21:05 PM

ANSWERS

What is a vitamin?
An organic compound which helps to regulate the processes of the body.
Why must vitamins be present in the diet?
Most vitamins cannot be synthesised by the body.
State the fat-soluble vitamins.
- Vitamin A.
- Vitamin D.
- Vitamin E.
- Vitamin K.
State the water-soluble vitamins.
- Vitamin C.
- The B complex vitamins: Thiamine (B1), Riboflavin (B2), Biotin, Niacin, Folic acid, Cyanocobalamin (B12), Pantothenic acid, Pyridoxine (B6).
Why is a frequent intake of water-soluble vitamins essential?
The water-soluble vitamins are readily lost via the urine and are poorly stored in the body; therefore a daily supply must be available in the diet.
Why is the risk of toxicity associated with excessive intake greater with fat-soluble than water-soluble vitamins?
The fat-soluble vitamins are stored far more efficiently within the body than the water-soluble-vitamins and therefore pose a greater risk of toxicity arising through excessive intake.
What is vitamin A also known as, and in which foods is it found?
Retinol. This is found in the yellow and orange pigments of most fruits and vegetables.
Why do cats require a pre-formed source of vitamin A?
Cats are unable to convert vitamin A from plant-derived beta-carotene and therefore require a pre-formed source of vitamin A found only in animal fat.
List the functions of vitamin A.
- Important for vision.
- Maintenance of cell structure.
- Sustenance of healthy skin and coat.
- Maintenance of mucous membranes.
- Bone and teeth development.
In what species in hypovitaminosis A common?
Terrapins. Ocular discharge and swollen eyelids become apparent.
When is hypervitominosis A most common?
Cats receiving a diet high in liver or oversupplementation with cod liver oil.
List the signs of hypervitaminosis A.
- Liver damage.
- Bone disease.
List sources of vitamin D.
- Cod liver oil.
- Fish.
- Dairy products.
Vitamin D is synthesised in the skin following exposure to sunlight.
What are the main functions of vitamin D? (Please refer to Module 4 - Minerals for further information).
- Stimulation of resorption of calcium from bone.
- Required for the intestinal absorption of calcium.
List sources of vitamin E.
- Egg yolk.
- Green vegetables.
What is the main function of vitamin E?
Protection of cell membranes against oxidative damage.
What sort of diet may give rise to vitamin E deficiency in cats leading to a painful inflammatory condition known as pansteatitis (yellow fat disease)?
A diet high in polyunsaturated fatty acids such as oily fish.
List signs of vitamin E deficiency in dogs.
- Skeletal muscle dystrophy.
- Reproductive failure.
- Immune response impairment.
What is the main function of vitamin K?
Regulation of the formation of blood clotting factors.
Why is vitamin K deficiency unlikely?
In the healthy animal, the daily requirement is easily met by synthesis by the gut bacteria.
Vitamin K is the antidote to which poison?
Warfarin.
List sources of vitamin K.
- Cod liver oil.
- Green vegetables.
What may give rise to vitamin B deficiency?
Avidin in egg white which binds biotin. Eggs should therefore be cooked prior to feeding.
Why should cats not be fed raw fish?
Thiaminases in raw fish may lead to thiamine deficiency; fish should therefore be boiled prior to feeding.
What is vitamin C also known as?
Ascorbic acid.
Most mammals can synthesise vitamin C from glucose. Which species commonly seen in practice is the most notable exception?
Cavies (guinea pigs).