vitamin e & k lecture 3 biochemistry
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VITAMIN EVITAMIN K
Dr. Vijay Marakala, MBBS, MD.
Assistant professor BIOCHEMISTRY SIMS & RC
VITAMIN E [TOCOPHEROL]
Chemistry Sources RDA Metabolism
Functions Deficiency Toxicity
VITAMIN E - CHEMISTRY
Tocopherolsα-tocopherol
β-tocopherol
γ-tocopherol
δ-tocopherol
Tocotrienolsα-tocotrienols
β-tocotrienols
γ-tocotrienols
δ-tocotrienols
VITAMIN E - CHEMISTRY
VITAMIN E – SOURCES
VITAMIN E – RDA
RDA 8 – 10 mg/day
The daily requirement increases with increase in dietary intake of PUFA
VITAMIN E – METABOLISM
Absorption
Upper SI
Along with lipids
Transport
Chylomicron
VLDL and LDL
Storage
Adipose tissue
liver
VITAMIN E – FUNCTIONS
As a biological antioxidantPrevents lipid peroxidation
of biological membrane
Prevents peroxidation of vitamin A & PUFA
Reproductive functions & prevents sterility
Vitamin E
VITAMIN E – FUNCTIONS
VITAMIN E & SELENIUM
Selenium complements the antioxidant effects of
vitamin E and reduces the requirement of vitamin E
VITAMIN E - DEFICIENCY
Causes Inadequate intake
Impaired absorption
Features Hemolytic anaemia in the new born
Muscle weakness
Spinocerebellar ataxia and impaired vision
VITAMIN K
VITAMIN K - CHEMISTRY
Pylloquinone
Present in plants
Vitamin K1
Menaquinone
Produced by intestinal bacteria
Vitamin K2
Menadione
Synthetic form
Vitamin K3
VITAMIN K - SOURCES
VITAMIN K - RDA
80µg/day
VITAMIN K - METABOLISM
Absorption
Upper SI
Along with lipids
Transport
Chylomicron
LDL
Storage
Liver
VITAMIN K - FUNCTIONS
Role in blood coagulation • Cofactor for gamma
carboxylation of glutamic acid in clotting factors II, VIII, IX and X
Role in bone mineralization• Cofactor for gamma
carboxylation of glutamic acid in osteocalcin
VITAMIN K - DEFICIENCYCauses In newborn
Impaired absorption
Sterile bacterial flora
Features
Bleeding
Prolonged prothrombin time
VITAMIN K - ANTAGONIST
Dicumarol Warfarin
VITAMIN K - ANTAGONIST