2. • Chemical name is tocopherol
• About 8 tocopherols have been isolated.
–α, β, γ & δ.
• α- tocopherol is most active.
• Derivatives of 6-OH chromane (tocol) ring with isoprenoid side chain
4. RDA of Vitamin-E
Adults- 8 to10 mg /day
Pregnancy & Lactation: 12 mg/day (15mg = 33IU)
Hyper vitaminosis –E
• At doses above 1000IU /day
• Cause tendency to hemorrhage, as it is mild anticoagulant.
5. • It absorbed along with fat in the small intestine with the help
of bile salts.
• Transported in the blood by chylomicrons
• It reaches the liver and stored in adipose tissue.
• The liver can export vit-E into VLDL to target cells.
Absorption, Transport & storage
7. • Vit-E act as a chain-breaking & free radical trapping in cell membranes.
• First line of defense against peroxidation of PUFA’s contained in cellular & sub
cellular membrane phospholipids.
• Terminates free radicals of the chain reactions of lipid peroxidation with the help of
selenium.
• Vit-E also prevents the non enzymatic oxidations of various cell components.
10. Deficiency of vitamin –E
Very rare in human
Fat malabsorption diseases
Deficiency can cause hemolytic anemia (due to oxidative damage to RBCs)
Peripheral neuropathy & retinopathy
Insufficiency of vitamin-E
Decreased production of Hb
&
shortened erythrocytes life spam
HEMOLYTIC ANEMIA
12. • Derivatives of naphthoquinone
Vitamin K1: Phylloquinone derived from plant.
Vitamin K2: Menaquinones, produced by micro-organisms
Vitamin K3: Menadione (Water soluble Synthetic product,
alkylated form of Vitamin K2)
Chemistry
20C isoprenoid side chain
30C isoprenoid side chain
13. Dietary sources
• Green leafy vegetables
• Even if the diet does not contains,
intestinal bacterial synthesis will meet the RDA
15. • Absorption takes place along with fat, and bile salts
• Transport in plasma with lipoproteins –Chylomicrons
• Stored in the liver
16. Biochemical Functions
– Required for the functional activity of osteocalcin
• It is a Ca+2 binding proteins (40-50 a.a’s length) synthesized by osteoblasts present
only in the bone.
• It binds tightly to hydroxyapatite crystals of the bone
• Binding is depends the degree of Vit–K dependent Carboxylase (γ-Carboxylation).
– Necessary for coagulation - Maintenance of normal blood coagulation.
17. A 2-year-old male child admitted to pediatric OPD, with features of
bleeding tendency - ecchymosis, hemorrhage in the mucous
membranes.
Investigations showed prolonged Prothrombin Time & delayed clotting
time. The condition improved with vitamin K administration.
1Q. What is the most probable diagnosis?
2Q: Role of vitamin K in coagulation
2Q. Inhibitors of vitamin K
Ecchymosis: Discoloration of the skin caused by bleeding underneath
Hemorrhage: Release of blood from broken blood vessel either inside or outside the body
22. Deficiency of Vit-K
• Can occurs in the malabsorption of lipids
• This can results obstructive jaundice, chronic pancreatitis &
• Gastrointestinal infections with diarrhea
• Will destroy the bacterial flora & can also leads to Vitamin K deficiency
23. Vitamin K Deficiency
Incomplete carboxylation of coagulation proteins
do not form complexes with Ca & phospholipid
Deficiency of Factors II,VII,IX,X
BLEEDING
24. Clinical manifestation of vitamin –K deficiency
Hemorrhagic disease
In newborn
In children & adults
Premature infants due to
- The lack of hepatic stores,
- Limited oral intake (breast milk has low
levels of Vit-K) &
- Absence of intestinal bacterial flora
Bruising tendency,
Ecchymotic patches,
Mucous membrane hemorrhage,
Post-traumatic bleeding
Nasal bleeding.
Ecchymotic patches: purple skin discoloration from rupture of blood vessels
25. • Prolongation of the PT & delayed clotting time are characteristic of Vit-K
deficiency
• Measurement of the PT is taken as an index of liver function
26. Vitamin-K injection is given to patients before liver & biliary
tract surgery, why give a reason
27. “If you cannot do
great things, do small things
in a great way.”
Have a great day to all
Editor's Notes
Role of vit –k in blood coagulation:-
It helps in the post transcriptional modification of blood factors such as prothrombin (II), VII, IX, and X (synthesized in the liver in inactive form).
Inactive form is converted to active form by Vit-K dependent carboxylation reaction.
This enzyme adds the extra carboxyl group at γ- carbon of glutamic acid residues of inactive blood clotting factors.
Negative charged (coo-) clotting factor combines with +ve charged Ca ions (Ca2+) to form prothrombin-Ca-complex.
In this complex binds to the phospholipids on the membrane surface of the platelets.
It leads to the increased conversion of prothrombin to thrombin.
Role of vit –k in blood coagulation:-
It helps in the post transcriptional modification of blood factors such as prothrombin (II), VII, IX, and X (synthesized in the liver in inactive form).
Inactive form is converted to active form by Vit-K dependent carboxylation reaction.
This enzyme adds the extra carboxyl group at γ- carbon of glutamic acid residues of inactive blood clotting factors.
Negative charged (coo-) clotting factor combines with +ve charged Ca ions (Ca2+) to form prothrombin-Ca-complex.
In this complex binds to the phospholipids on the membrane surface of the platelets.
It leads to the increased conversion of prothrombin to thrombin.
Warfarin is a synthetic analogue inhibits vit –k action.
And also required for the functional activity of osteocalcin and Ca+2 binding proteins present in bone.