Vitamin A Flashcards
(34 cards)
formula for Vitamin A
C20H30O
active as an alcohol, aldehyde, acetate, palmitate, and an acid
Vitamin A
_____ will not fullfill visual purple and reproduction requirements
retinoic acid
most popular synthetic form of Vitamin A
Vitamin A palmitate
true or false. Vitamin A occurs only in animals
true
where is Vitamin A the highest
liver
colostrum contains ____ times as much Vitamin A as other milk
10
2 things that improve vitamin A absorption
bile and fat
7 functions of vitamin A
- role in visual purple cycle
- maintenance of normal epithelium
- involved in normal bone formation- slow osteoblast differentiation is deficient
- nervous symptoms- due to failure of spinal and some other bones to develop
- total blindness (may be due to pinching of optic nerve)
- maintenance of normal cerebrospinal fluid pressure
- necessary for normal reproduction
a vitamin A defficiency does not allow for enough _____ synthesis and results in night blindness
rhodopsin
a compound that breaks down, in the process of sight, as a result of a photochemical process
rhodopsin
11 deficiencies of Vitamin A
- reduced appetite
- night blindness
- xerophthalmia
- runny eyes in cattle & sheep
- eyes sticking together in chickens
- increased keratinization of epithelium = more infections
- increased respiratory problems
- vaginal, reproductive tract problems, etc.
- formation of kidney stones
- malformation in certain soft tissue (pigs w/o eyes & hydrocephalic rabbits)
- liver & kidney damage
- diahhrea
- testicular degeneration in males (reversible)
7 symptoms of hypervitaminosis A
- skin thickening
- interference with bone development
- prolonged prothrombin time
- increased in cerebrospinal
- lowered plasma cholesterol in chicks
- reabsorption of fetus
- decreased appetite
what causes skin thickening from hypervitaminosis A
suppressed keratinization & mucous secretion
how does hypervitaminosis A interfere with bone development
loss of chondroitin sulfate from the matrix
what cures prolonged prothrombin time
K (potassium)
in what species is carotene not absorbed but converted to vitamin A in intestinal wall
“white-fat species” – rats, sheep, goats, pigs
what species has carotene in plasma and only converts some carotene from feed into vitamin A
“yellow-fat species” –cow, horse
- carotene in plasma may be stored in liver and fatty tissues
main storage area for vitamin A
liver
what percent of vitamin A is found in the liver
70-90%
sources of vitamin A
vitamin A - fish oils
carotene
has the most effect on Vitamin A
esterification
has the least effect on Vitamin A
hydrogenation & heat in the absence of moisture (no effect)
generalized vitamin A requirement for mammals
20-100 IU/kg BW
poultry is 5x that amount
