Fat Soluble Vitamins Flashcards
what amount vitamins is required
minute quantities
what happens in omission of single vitamin
specific deficiency and symptoms
what are the fat soluble vitamins
A, D, E, K
what are the water soluble vitamins
B1, B2, B3, B6, B12, C
chemical name of vitamin A
Retinol
what is vitamin A required in and in what forms
the diet, as the vitamin or its precursor carotene
sources of vitamin A
liver of cod/halibut, egg yolk, milk fat
what is a provitamin
a substance that is converted into a vitamin within an organism
what are the provitamins of vitamin A called
carotenoids
what are examples of carotenoids
carotenes and xanthophylls
what does ultraviolet light exposure do to vitamin A precursors
destroys double bonds and biological activity
what easily oxidizes vitamin A
heat, light, moisture, heavy metals, air, light
what % of vitamin A is converted in liver
90%
where is vitamin A converted
intestinal mucosa (mixed micelles) but mostly in liver
what does vitamin A content in liver directly relate to
ingestion of the vitamin in the diet
what is retinal
vitamin A occurring as an alcohol
what is beta-carotene composed of
2 joined vitamin A molecules
what is retinoic acid
free form of vitamin A
what is vitamin A palmitate
retinoic acid esterfies with a fatty acid
what is most stable vitamin A form
retinoic acid (palmitate)
what two things is vitamin A metabolized for
the eye and general systems
why is vitamin A important for the eye
needed for creation of rhodopsin
what is rhodopsin
low light receptor
what is vitamin A used for in general systems
differentiation and formation of epithelial tissues/ mucous membranes and is a free radical scavenger
what does vitamin A do in the general systems as a free-radical scavenger
is an antioxidant, anticarcinogenic, and antimutagenic
what three things combine to form rhodopsin
retinal+opsin+vitamin A
what happens in vitamin A deficiency
impaired ability to see in dim light, hyperkeratinization of skin, roughened hair/plumage, low levels of immunoglobulins
what is vitamin A deficiency rare in and why
grazing animals b/c they eat plants with high carotene content
what is vitamin A deficiency most susceptible in and why
pigs and poultry, has to do with husbandry and the proper kinds and amounts being added to diet
what color are vitamin A provitamins
yellow, orange, red
what time of year/weather are vitamin A deficiencies and why
winter months and drought, because of insufficient green forage
when does vitamin A toxicity happen when not being excreted readily
long term ingestion of daily intake >50-500 fold the requirement
at what single dose of vitamin A toxicity has death occurred
500,000-1 million IU (industrial unit)
what are some signs of chronic vitamin A toxicity
anorexia, weight loss, thickened scaly skin, edema, crusty eyelids, alopecia, hemorrhaging, decreased bone strength, spontaneous fracture, death
what happens with vitamin A toxicity while pregnant
malformed young (cleft palate, abnormal skull/skeleton, atresia-oculi)
chemical name of vitamin D3
cholecalciferol
is vitamin D2 or D3 more stable
D3
what is the water soluble version of vitamin D3
milk-sulphate derivative
chemical name of vitamin D2
ergocalciferol
vitamin D is —– susceptible to oxidation than vitamin A
less
what is the only abundant source of vitamin D
certain fishes (halibut and cod)
what is a plant source of vitamin D
dried plants
what is a small animal source of vitamin D
tissues (egg yolk, milk)
vitamin D is limited in what
plants and animals
what are the provitamins of vitamin D
7-dehydro-cholesterol, Pre-D3 cholecalciferol, 25 hydroxy D3
what converts vitamin D provitamins to their active form
UV light
where is Pre-D3 converted to 25 hydroxy D3
liver
where is 7-dehydro-cholesterol converted to Pre-D3
skin
exposure to sunlight does what
converts sterols to Vit D3