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



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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








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