Vitamin K Flashcards
What is Vitamin K “claim to fame”
Coagulation (blood clotting)
What is the synthetic form of Vitamin K
Menadione (K2)
What is the plant source of Vitamin K
Phylloquinone (K1)
What is the animal source of Vitamin K
Menaquinone-7 (MK-7)
What source of Vitamin K is synthesized by gut bacteria in the colon
Menaquinone-7 (MK-7)
What is the mechanism Vitamin K is involved in
Post-translational modification of protein
Vitamin K is a cofactor for what enzyme (involved in protein modification)
glutamyl carboxylase
What is the function of the enzyme Glutamyl carboxylase
Adds a carbon compound to the protein (carboxylates protein)
What is the active form of Vitamin K
Vitamin K quinone/Dihydroquinone
What is the inactive form of Vitamin K
Vitamin K 2,3 epoxide
What is the relationship between Vitamin K and bones
Cofactor for Osteocalcin (carboxylation)
What clotting factors bind to Calcium in order to be active
II, VII, IX and X
What clotting factor requires carboxylation to bind to Calcium
Factor II
What clotting factor requires Vitamin K
Factor II
What is being formed during blood clotting (cascading series of reactions)
Fibrinogen
What is Warfarin
Anticoagulant medication; “blood thinner”; reduces clotting quality of blood
Which enzymes convert Vitamin K 2,3 epoxide back to active form
Epoxide reductase and Quinone reductase
How does anticoagulant reduce blood clotting
Inhibits 2 reductases that convert Vitamin K to active form
What is Vitamin K intake for person taking anticoagulant
Constant/consistent intake; drug titrated according to intake
What is the UL for Vitamin K
None
What is the RDA for Vitamin K
120ug
What are food sources of Vitamin K
Brussel sprouts (cruciferous vegetables). leafy greens, white beans, asparagus
What is the concern for newborns and Vitamin K? Why?
Hemorrhagic disease; Born with little Vitamin K, given injection immediately until can produce in gut/intake in diet (10-12days)
