Vitamin E Flashcards
Vitamin E is in how many vitamers
8
what are the 8 vitamers of vitamin E
4 tocopherol w SATURATED side chains
4 tocotrioenols with UNSATURATED side chains
what carbon is the hydroxyl group of the vitamers attached to
C6
_____ has the highest biological activity of all the vitamers
alpha tocopherol
_______ is the only form of vitamin E recognized as being able to meed the human requirements
alpha tocopherol
the biologically active form and the only form found naturally in humans
NATURAL alpha tocopherol (RRR a-tocopherol)
mixture of 8 sterioisomers, which half are not biologically active
synthetic alpha tocopherol
sources of vitamin e
plant oils
nuts
grains
green veggies
stability of vitamin E
oxidized with lengthy exposure to oxygen light or heat
tocopherols are found free in foods but ______ ester forms from supplements require hydrolyzation before absorption
synthetic
______ are found esterified in foods and therefore also require hydrolyzation
tocotrienols
all forms of vitamin e are ______ and require ____ for micelle formation
fat soluble, bile
vitamin E is absorbed primarily in? and how?
jejun by passive diffusion
once inside the enterocyte, tocopherols and tocotrienols are incorporated into _____ for ransport
chylomicrons
during transport, tocopherons and tocotrienols are transferred among-____
lipoproteins
where do we find the highets amounts of vitamin e in circulation
lipoproteins
chylomicrons bring the remaining vitamin E to the?
liver
the liver incorporates ____ in VLDLs for recirculation into blood and extraheptic tissus
RRR-alpha-tocopherol
vitamin e is primarily stored
adipose tissue
functions of vitamin e
antioxidant - fat cells from free radicals
platelet aggregation inhibition ( anti vitamin K activity)
the major route of excretion is through
the feces via bile
consumtion of large amounts of ______ increased requirements of vitamin E
PUFAs
those who smoke have an _____ vitamin E requirement
increased
vitamin e deficiency is rare but is seen in
people with fat malabsorption issues (cystic fibrosis, choestatic lv dz)
clinical indications for vitamin E supplementation
heart disease - lowers risk of coronary heart disease
alpha tocopherol decreases oxidation of ___ by free radicals
LDL
g-tocopherol inhibits
platelet aggregation
alphatocopherol and g tocopherol prevent
development of atherosclerotic lesions and lower the risk of coronary heart dz
signs of vitamin e toxicity
impaired blood coagulation
n/d flatulence
mm weakness fatigue
double vision
Vitamin E functions together with ______ as part of antioxidant defense system recycling each others redox activity
vitamin c
two metabolites of vitamin E have anti _____ activity
vitamin k
