vitamins

Question 1

what is a vitamin?

Answer 1

organic compounds that are required in small amounts for normal growth and maintenance of the animals life.
a component of a natural food, bit is distinct from other nutrients.
a cause of a specific deficiency disease or syndrome if absent from the diet or if improperly absorbed or utilised.
sometimes synthesised by the animals but not in sufficient amounts to meet physiological demands and therefore must be obtained from the diet.

Question 2

history

Answer 2

Lind( 1753)= British naval physician- published a paper on the incidence and prevention of scurvy with salads and summer fruits.
hopkins(1912)= rats- essental factors.
funk(1913)= thought amino-nitrogen compounds (‘vital amines’) were the essential factors.
by 1919 at least 4 were postulated.

Question 3

what do we need to know about vitamins?

Answer 3

easily damaged: heat, light, contact with metals; use-by date= viability of the vitamin content of the feed.
divided into groups: fat soluble and water soluble.

Question 4

FSV: vitamin A

Answer 4

known as retinol, toxic in high quantities, removed and stored in the liver: a good source.
can be manufactured. present in plants as beta-carotene.
deficiency is ‘night blindness’
not necessarily due to vitamin A
vitamin A involved in Rhodopsin
infection
toxicity
irritability, painful joints, growth retardation, liver and spleen enlargement, hair loss and birth defects.

Question 5

FSV: vitamin D

Answer 5

many forms are known
D2 Ergocaliferol(plants)
D3 Cholecalciferol(animals)
Deficiency: rickets, deposition of calcium and phosphorus are affected, bones are weak and brittle, back ache.
anorexia, muscle weakness, polyuria, joint pain and stiffness, hypocalcemia, low immunity
toxicity- unlikely.