Date post: | 23-Aug-2014 |
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WATER SOLUBLE VITAMINS
Dr Vijay Marakala MBBS.,MD.Assistant professor
BiochemistrySIMS&RC
Vitamin C
Published “Treatise
on Scurvy” in
1753
VITAMIN C
Many animals can synthesize ascorbic acid from glucose via uronic
acid pathway.
Humans cannot synthesize
vitamin C due to deficiency of L-gulonolactone
oxidase
Vitamin C - CHEMISTRYStructural formula closely resembles that of
carbohydrates
VITAMIN C - SOURCES
VITAMIN C- RDA
RDA
60mg for adults
70mg for pregnant women95mg for lactating women100mg for smokers
VITAMIN C- Absorption
Readily absorbed
from gastrointesti
nal tract
VITAMIN C - FUNCTIONS
Ascorbic acid act as antioxidant
Hydroxylation of proline and lysine
Steroid biosynthesis
Catecholamine synthesis
from tyrosine
Bile acid synthesis
Absorption of iron in
the intestine
Catabolism of tyrosine
Folate metabolism
VITAMIN C - FUNCTIONS
As antioxida
nt
Regenerates functional tocopherol
Prevention of
atherosclerosis
Prevention of cancer
Hydroxylation of proline and lysine
Post-translational hydroxylatio
n
For collagen biosynthesis
Catecholamine
synthesis from
tyrosine
IRON ABSORPTION
Vitamin C enhances the iron
absorption from
intestine
Catabolism of tyrosine
Parahydroxy phenylpyruvate hydroxylase
Vitamin C
Vitamin C
Vitamin C
Folate metabolism
VITAMIN C – DEFICIENCY MANIFESTATIONS
Haemorrhages in various tissues
General weakness and anaemia.Swollen joints,
swollen gums and loose tooth.
Susceptible for infections.
Delayed wound healing.
Bone fragility and osteoporosis.
SCURVY
Scurvy
Periodontal disease Bleeding gum Scurvy
THERAPEUTIC USES OF VITAMIN C
Common cold Cancer
Toxicity of vitamin C
Up to 2-3g/day can be taken
More than 3g/day
undesirable