Vitamin k is a group of lipophilic, hydrophobic vitamins. Vitamin k is a group of lipophilic, hydrophobic vitamins

Vitamin K is a group of lipophilic, hydrophobic vitamins.

• Vitamin K is a group of lipophilic, hydrophobic vitamins.

• They are needed for the postranslation modification of proteins required for blood coagulation,

• They are involved in metabolism pathways, in bone mineralisation, cell growth, metabolism of blood vessel wall.

Vitamin K1 (phylloquinon) – plant origin

• Vitamin K1 (phylloquinon) – plant origin

• Vitamin K2 (menaquinon) – normally produced by bacteria in the large intestine

• K1 a K2 are used differently in the body

• K1 – used mainly for blood clothing
• K2 – important in non-coagulation actions - as in metabolism and bone mineralization, in cell growth, metabolism of blood vessel walls cells.

Cofactor of liver microsomal carboxylase which carboxylates glutamate residues to -carboxyglutamate during synthesis of prothrombin and coagulation factors VII, IX a X (posttranslation reaction).

• Cofactor of liver microsomal carboxylase which carboxylates glutamate residues to -carboxyglutamate during synthesis of prothrombin and coagulation factors VII, IX a X (posttranslation reaction).

• Carboxylated glutamate chelates Ca2+ ions, permitting the binding of blood clotting proteins to membranes.

• Forms the binding site for Ca2+ also in other proteins – osteocalcin.

Vitamin K serves as an essential cofactor for a carboxylase that catalyzes carboxylation of glutamic acid residues on vitamin K-dependent proteins. These proteins are involved in:

• Vitamin K serves as an essential cofactor for a carboxylase that catalyzes carboxylation of glutamic acid residues on vitamin K-dependent proteins. These proteins are involved in:

• 1) Coagulation 2) Bone Mineralization 3) Cell growth

Deficiency is caused by fat malabsorption or by the liver failure.

• Deficiency is caused by fat malabsorption or by the liver failure.

• Blood clotting disorders – dangerous in newborns, life-threatening bleeding (hemorrhagic disease of the newborn).

• Osteoporosis due to failed carboxylation of osteokalcin and decreased activity of osteoblasts.

• Under normal circumstances there is not a shortage, vit. K is abundant in the diet.

Green leafy vegetables

• Green leafy vegetables

• vegetable oil

• broccoli

• cereals

The transformation of liquid blood into a solid gel

• The transformation of liquid blood into a solid gel

• Stops blood flow in the damaged area

• Fibrin is the final protein which produces a meshwork to trap RBC and other cells

Certain clotting factors/proteins require calcium to bind for activation

• Certain clotting factors/proteins require calcium to bind for activation

• Calcium can only bind after gamma carboxylation of specific glutamic acid residues in these proteins

• The reduced form of vitamin K2 (vitamin KH2) acts as a cofactor for this carboxylation reaction.

• These proteins are known as “Vitamin K dependent” proteins

factor II (prothrombin)

• factor II (prothrombin)

• factor VII (proconvertin)

• factor IX (thromboplastin component)

• factor X (Stuart factor)

• protein C & protein S

• Protein Z