Vitamin E and K in a simplified version for exams and Revision

1. Vitamin E (Tocopherols)
• It is naturally occurring antioxidant
•Essential for normal reproduction in animals. Hence it known as “anti
sterility vitamin”
•Greek
• toco – child birth
• pheros – bear
• ol – alcohol
Chemistry:
•There are 8 types tocopherols have been identified in nature. They are α,
β, γ, δ etc.., among these α tocopherol is most active
• tocopherols are derivatives of 6 hydroxy chromone ring with isoprenoid
side chain
•The anti oxidant property is mainly due to chromone chain
Absorption, transport and storage
•vit E absorbed along with fat in small intestine and bile salt also essential
for absorbtion

3. Transport: it transport by lipoprotein (VLDL and LDL)
Storage: adipose tissue, liver and muscles
Biochemical function
• it is most powerful natural antioxidant so it prevent the non
enzymatic oxidation of various cell components by free radicals
• It protects poly Unsaturated Fatty acids(PUFA) from peroxidation
reaction
• It is essential for membrane structure and integrity of cell. Hence
it regarded as a membrane antioxidant
• It prevents sterility. It preserves and maintain germinal epithilium
of gonads for proper reproductive function.
• It increase synthesis of heme by enhance the acivity of
AminoLevulinic Acid (ALA) synthase(rate limiting enzyme of
Heme synthesis)

4. • It requires for cellular respiration by ETC(electron transport chain)
• It prevents oxidation of vit A and carotenoids
• It requires for proper storage of creatine in skeletal muscles
• It requires for optimal absorption of aminoacids
• It protects liver being damaged by toxic compounds
• For proper synthesis of nucleic acids
• Reduce the risk of atherosclerosis
• It works along with vit A, C and beta carotene and delay onset of
cataract
• Vit E has been recommended for prevention of cancer and heart
diseases
• It protects RBC from hemolysis by H2O2
• Normal blood tocopherol is 0.5 to 1mg/dl.
RDA
Male – 10mg/day
Female – 8mg/day
Pregnancy – 10mg/day
Lactation - 12mg/day

5. • Vit E and selenium are functionally same
Dietary source:
Rich source – vegetable oils
Good source – wheat germ oil, cotton seed oil, peanut oil, corn oil
and sunflower oil
Moderate source – meat, milk, butter and eggs
Deficiency symptoms
Sterility, degenerative changes in muscles, megaloblastic anemia and
changes in central nervous system. At severe deficiency, fragility
of erythrocyte and minor neurological symptoms are seen
Toxicity
compare to other vitamins, it less toxic even if it consume in excess
and there is some chance to cause tendency to hemorrhage

6. Vitamin K
• It is fat soluble vitamin with a specific coenzyme activity and it require for
production of blood clotting factors. It is otherwise Anti haemorrhagic factor
• The term K is the abbreviation of the German word ‘Koagulation
Vitamin’.
• Chemistry
• They are naphto-quinone derivatives with long isoprenoid side chain
• It exist in 3 forms
• K1 – phylloquinone - plants,
• K2- menquinone produced by intestinal bacteria,
• K3 – menadione a synthetic form.
These three vitamins are heat stable
Absorption and storage
• it taken through diet or synthesized intestine and it absorbed along with
fat in presence of bile salts.
• It transported by LDL and it mainly stored in liver and some extent to
tissue

8. Biochemical functions
• Vit-K is necessary for blood coagulation.
• Factor II ( Prothombin) , Factor VII, Factor IX (Christmas
factor),Factor X (Stuart Prower factor) are synthesized by the
liver as inactive zymogens.They undergo post-translational
modification-Gamma carboxylation requires Vit-K as a co-
factor
• Vit k also essential for carboxylation of glutamic acid residue
of osteocalcin, a calcium binding protein present in the bone
• It also essential for the conversion of glutamate to γ carboxy
glutamate which inhibits the activity of Dicumerol, a
anticoagulant( prevent the coagulation (clotting) of blood. )
• Vit.k deficiency caused by malabsoprtion of lipids,
obstructive jaundice, steatorrhoea, chronic pancreatitis,
Prolonged antibiotic therapy and GI infection with diarrhoea
will destroy the bacterial flora and can lead to vitamin
deficiency.

9. ( Factor II ( Prothombin) , Factor VII, Factor IX
(Christmas factor),Factor X (Stuart Prower factor))
synthesized by the liver as inactive zymogens.
Post Translational Modification
Vit. K & Gamma Carboxylation
(co factor)
Active form

10. In children and adults Vit-K deficiency is manifested as :
1. Bruising tendency (Hematoma of tissue)
2. Echymotic patches (bluish discolorisation of an area of skin caused by
extravasation of blood into subcutenous tissue)
3. Mucous membrane hemorrhage.
4. Post traumatic bleeding and internal bleeding.
5. Prolongation of prothrombin time lead to delayed clotting time are
characteristic of Vit-K deficiency.
• DAILY REQUIREMENT OF VITAMIN –K:
50 to 140mcg/day. This is available in a normal diet.
• SOURCES:
Green leafy vegetables, cabbage, cauliflower, tomatoes, egg yolk, meat,
liver, cheese and dairy products
• HYPERVITAMINOSIS:
Haemolysis, hyperbilirubinemia, hemolytic anemia, jaundice
 Antagonists of vit K : Heparin, bishydroxy coumarin, salicylates, and
dicumarol.

12. • Bruishing tendancy Echymotic patches
• membrane hemorrhage