water soluble vitamins vitamin c ppt lecture 3 biochemistry vkunder637@gmail.com

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