Vitamin K is essential for blood clotting as it is required for the production of proteins involved in coagulation like prothrombin. There are two forms - K1 derived from plants and K2 produced by intestinal bacteria. Vitamin K acts as a cofactor for the gamma carboxylation of glutamic acid residues in clotting factors to enable their biological activity in clot formation. A deficiency can result in bleeding issues as it decreases the synthesis of factors II, VII, IX and X.

1. 1

2. 2

3. VITAMIN K
Antihemorrhagic /coagulation vitamin or
prothrombin factor.Two variants K1
and,K2 .All are napthoquinone derivatives.

4. 4
VITAMIN K (PHYLOQUINONE)
It is essential for production of a type of protein
called prothrombin & other factor involve in
blood clotting mechanism. Hence it is known as
anti – hemorrhagic vitamin.

5. • The basic structure of vitamin K is 1,4-
naphtoquinone. Its vitamin activity depends
on the methyl group in position two, while
its fat solubility and other properties are due
to the long side chains. Vitamin K2 is a
collective term for menaquinones with side
chains of different lengths-always with an
iso-prene unit attached.

6. 6
Forms
It is available in 2 forms
K1 – it is the form occurs in plant origin.
K2 - is synthesized by intestinal bacteria.

7. • Phylloquinone (vitamin K1) is present in
variable concentriations in the chloroplasts
or green plants, where it is needed for
photosynthesis. Gram-positive bacteria,
like certain strains of Escherichia coli and
Bacteriodes fragilis produce
menaquinones (vitamin K2),

8. SOURCES
• Cabbage
• Cauliflower
• Tomato
• Alfa alfa
• Spinach
• Green leafy
vegetables
• Egg yolk
• Meat
• Liver
• Cheese & dairy products
RDA: 70-140 microgm/day

9. Structure of vitamin K

11. 11
ABSORPTION ,STORAGE, EXCRETION
ABSORPTION
small intestine
STORAGE 
liver adipose tissue
EXCRETION 
urine

12. BIOLOGICAL ACTIONS OF VITAMIN-K
1. Vitamin-K is needed for formation of
proconvertin: It is needed for the formation
of prothrombin. Deficiency of vitamin K
decreases proconvertin level in blood.
2. Vitamin-K modifies prothrombin: Vitamin-K
is a coenzyme in modification of
prothrombin to thrombin.

13. 3. Vitamin-K modifies other clotting factors
also: Vitamin K is needed for maintenance
of normal levels of blood clotting factors II,
VII, IX and X.

14. 3. Their conversion to biologically active
forms depends upon vitamin K. The
activation involves carboxylation of
glutamyl residues in the molecules of
these factors (including prothrombin
also) to form dicarboxylic glutamyl
residue.

15. 4. Vitamin-K is needed for carboxylation of
glutamyl residue of Ca++
binding transport
between the flavin coenzyme and the
cytochrome system.

16. FUNCTIONSFUNCTIONS
• Vitamin K is essential for coagulation. Factors II
(Prothrombin), VII (Proconvertin), IX
(Christmas factor), X (Stuart Prower factor)
• Proteins (Zymogens)
»Post Translational modifications
»Functionally active

17. Gamma Carboxylation of GlutamicGamma Carboxylation of Glutamic
acidacid

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FUNCTIONS
it is essential for the hepatic synthesis of
coagulation factor II, V, VII, IX, X.
CLOTTING – it prevents hemorrhage only in
cases when there is defective production of
prothrombin
OXIDATIVE PHOSPHORYLATION – it
acts as a co- factor in oxidative
phosphorylation associated with lipid

19. FACTORS CAUSING VITAMIN-K
DEFICIENCY:
• Surgical removal of intestine:
• Liquid paraffin:
• Antibiotic therapy for a long time:
• Vitamin-K antagonists: Heparin and warfarin

20. long term administration of antibiotic doses for
more than a week may temporarily suppress
the normal intestinal flora may cause
deficiency of vit k

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DAILY REQUIRMENT
men and women – 70 – 140 mcg.
children – 35 – 75mcg

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DEFICIENCY
Causes
Decrease
synthesis of
factor 2,7,9,10 Increase clotting time
Prolong bleeding
Hemorrhagic
conditions
After antibacterial
therapy,
Surgical operations-
Cholecystectomy
Conditions like
Malabsorption
Obstructive
jaundice

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25. 25

26. 26

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29. 29

30. Vitamin - K Deficiency
• Deficiency causes:
• Bleeding of gums
• Dark circles under eyes
• Bleeding

31. HYPERVITAMINOSIS K
Hemolytic anemia and jaundice (in large
doses)
ANTAGONIST TO VITAMIN K
Heparin, Dicumarol, Salicylates

32. Misuses
• Prolonged consumption of megadoses of
vitamin K (menadione) results in anemia,
which is a reduced level of red blood cells
in the bloodstream.