Vit K

Question 1

Important in

Sources of VK1 (phytonadione/phylloquinone)

Gut synthesizes

Answer 1

coag pathways

from leafy green veggies

VK2 (menaquinone)

Question 2

Absorption requires

Dietary VK is

Bile salts help to

Incorporated into

Answer 2

intact fat absorbing mechs

protein bound, liberated by proteolytic action of panc enzymes in SI

solubilize VK into micelles for absorption to enterocytes

chylomicrons for transport to liver

Question 3

VK is ___ for key enzymes in coag

Necessary to activate

Protein C and S

overriding effect of VK deficiency is

Answer 3

cofactor

Factor 2 (prothrombin), 7, 9, 10 (arrest and prevent bleeding)

anticoag, require VK

bleeding due to inactive coag proteins

Question 4

Factors contain, carboxylated by

VK is

After carboxylation

Answer 4

carboxyglutmin acid, carboxylated by glutamy carbolxylase

active coenzyme, providing energy for rxn through oxidation

proteins gain affinity for neg charged phospholipids on surface of platelets, leading to coag

Question 5

Warfarin

Interrupts

VK supplementation inhibits

Answer 5

similar in structure to vk

VK dependent carboxylation cycle, blocks VK- inhibits coag

warfarin effects

Question 6

Deficiency

Such as

Severe parenchymal LD leads to

Answer 6

any cause of fat malabsorption

TPN, long term AB, prolonged fasting

def of VK dependent coag factors (synthesized in liver)

Question 7

VK def commoner in

newborn does not

stores low bc

CM

must be

Answer 7

newborns- bleeding

utilize VK

VK content of breast milk/sterile gut/poor placental transfer

cutaneous bruising or bleeding from mucosal surface/GI tract/umbilicus/circumsision/IC hemorrhage

admin at birth

Question 8

VK def manifests as

Pt w liver dz

if PT does not improve w VK

Answer 8

inc PT and INR

inc PT because of cell destrxn, VK def

likely due to liver dysfxn

Question 9

Toxicity

Answer 9

impair warfarin