Vit K Flashcards
what is the name of the plant form of Vit K?
phylloquinone
what are sources of K1?
green leafy veg, some seed oils
what is the name of the bacterial form of Vit K?
menaquinones (K2)
found in fermented foods
MK7
made in our body
MK4
synthetic form of vit K
menadione (K3)
where is menadione used?
in the animal feed industry
T or F: We have lots of vitamin K stored in our liver
False
Vitamin K is a cofactor for _____ proteins
calcium binding
Vit K adds a carboxy group to the a.a. ___ to form ___, when it is in the active form called ___
Glu; Gla; hydroquinone
this enzyme converts fibrinogen to fibrin, inducing clot
thrombin
what is the precursor to thrombin?
prothrombin
prothrombin circulates in ___ and is made in the ___
plasma; liver
Why is conversion of Glu–>Gla important?
allows prothrombin to bind Ca to become thrombin
how is Vit K regenerated?
through K epoxide
the cycle is blocked by this drug
warfarin (coumadin)
Vit K is required in bone formation, to make ___
osteocalcin (to bind calcium) and matrix Gla protein
what does MK4 possibly do?
support brain function, sphingolipid metabolism
what causes secondary deficiency?
lack of bacteria (antibiotics), newborns have sterile gut, fat malabsorption, vit E excess, coumadin use
what is the AI based on?
median intake of healthy groups in US
the AI for females is ___ and for males is ___
90 mcg; 120 mcg
how to assess static status?
plasma levels of K1
how to assess functional status?
prothrombin time (time for blood to clot)-->should be 11-14 sec -also look at undercarboxylated prothrombin lvls in plasma
