2. VITAMIN C
• It is a water soluable.
• Vitamin C is not stored in the body but is
taken by all the tissues
• High level of vit C is found in the pituitary
glands.
• Also known as L-ascorbic acid it is an essential
nutrient for humans.
• Ref:american journal of paed. 2001
3. HISTORY OF VITAMIN C
• 17th century – sailors got scurvy on ships and
ship surgeon, James Lind, prescribed lemon
juice as preventative. Performed an
experiment that proved that lemon juice
prevents scurvy.
• We now know today that it is because of the
Vitamin C in the lemon that prevents scurvy or
a vitamin C deficiency
4.
5. CHEMISTRY
• It is L-Ascorbic Acid.
• its oxidized derivative L-dehydroacorbic.
• The acidic property of vitamin C is due to enolic
hydroxyl groups.
• It is a strong reducing agent. They form a
reversible redox system
• Oxidation of ascorbic acid is rapid in the
presences of copper..Hence ,vit C becomes in
active if the foods are prepared in copper vessels.
7. SOURCES
• Mostly in citrus fruit and juices
(limes, lemons, oranges, strawberries, banana
s, and grapefruits)
• Also in
cabbage, broccoli, cauliflower, tomatoes, potat
oes, and beans.
• There are also vitamin C pills and other things
for supplements.
• Ref:leninger biochemistry
8. SYNTHESIS
• All Plants can synthesize Vitamin C
• Most animals can synthesize vitamin C except
: Humans, Guinea pigs, fruit eating bat
• They lack: L-gulono-γ-lactone oxidase
9. BIO CHEMICAL FUNCTION
• 1.COLLAGEN FORMATION: vit C Plays the role
Of a coenzyme in hydroxylation of proline and
lysine .
The hydroxylation reaction is catalysed by lysyl
hydroxylase (for lysine) and propyl
hydroxylase(for proline).
The hydroxyproline and hydroxylysine are
essential for the collagen cross-linking and the
strength of the fibre.
10. 2.Bone formation
• Bone tissues possess an organic
matrix, collagen and the inorganic
calcium,phosphate
2.Iron and hemoglobin metabolism:Ascorbic
acid enhances iron absorption by keeping it in
the ferrous form. This is due to the reducing
property of vit C.
11. 3.Tryptophan metabolism
• Vitamin C is essential for the hydroxylation of
Tryptophan to hydroxytryptophan in the
synthesis of serotonin by hydroxylase.
4.Folic acid metabolism:
The active form of the vitamin folic acid is
tetrahydrofolate.
Vitamin C is needed for the formation of
tetrahydrofolate.
12. 5.Synthesis of corticosteroid hormones
• Adrenal gland possess high level of ascorbic
acid particularly in period of stress.
• It is believed that vit C Is necessary for
hydroxylation reaction.
• 6.immunological function: vitamin C
Enhances the synthesis of immunoglobins.
13. 7.Preventive action on chronic disease
• Free radicals are constantly produced in the
Normal metabolism .they cause serious damage
To proteins ,lipids,DNA and the cell membranes.
These free radical are implicated in the
development of cancer, heart diseases .vit C
prevent from these diseases.
14. Dietary needs
• The recommended daily intake for
Infants: 0-6month :40mg/day
7-12 month: 50 mg/day
Children :1-3yr :15mg/day
4-8yr: 25mg/day.
Dr. Linus Pauling believes that 10 grams a day will
prevent cancer.
15. Clinical manifestation:
• 1.age of onset is between 6 and 24 month
• 2.Due vitamin C def. symptoms such as
irritability, tachypnea,digestive disturbances
and loss of appetite.
• 3.pain in the limbs :limbs are like frog like
position with hips and knees semiflexed with
feet rotated outward.
• 4.edematous swelling along the shaft of legs.
16. • 5.anaemia may be present due to
bleeding,decrease absorption of iron and
defective conversion of folic acid.
• 6.purpuric ,petechiae and ecchymosis may be
present.
• 7.a rosary at the costochondral junctions and
Depression of the sternum.
17. Investigations :
• 1. Decrease of vitamin C LEVEL in blood
Normal 0.6mg/dl
2.Vit C loading test:10 mg /kg of vit C is given
and more than 80% of it is excreted in urine. If
excretion is less than 20%.-It indicates
deficiency of vitamin C.
3.VIT C LEVELS are decreased in WBC and
platelet buffy coat.
18. Management
• 0ral preparations are preferred to parenteral
dose
• Dose 0- 6 month :40 mg/day
• 7-12 month :50mg/day
• 1-3 year : 15mg./day
• 4-8 yr :25mg/day.
19. Scurvy
• It is a nutritional disorder due to deficiency of
ascorbic acid(vitamin c).
PATHOLOGY
1.Rarefaction of shaft and epiphysis resembling
Ground glass appearance.Thinning of cortex is
present.
2.Thickening of zone of provisional calcification is
seen at epiphysis due to defective proliferation of
cartilage cells. It is brittle and fractures may
develop.
20. • 3.subperiosteal haemorrahages are seen due
To leaking of blood from vessels,resulting in
stripping of periostium.
4. Dentin is defective due to defective formation
Of collagen resulting spongy gums and bleeding
from gums.
22. • 8.perifollicular bleeding
• 9.anaemia may be present due to
• A)bleeding
• B)decrease in absorption of iron
• C)defective conversion of folic acid.
• 10.delayed wound healing.
• 11. scorbutic rosary: a groove is present in
between costal cartilage and rib due to
depression of cartilage.
23. X.Ray of bones
• 1.Wimberger’s sign: rarefaction and thickening
• Of outerline of epiphysis.
• 2.white line of frankel:thickening of zone of
provisional calcification
Cartilage proliferation is seen at the epiphyseal end
of long bones.
3.pelken’s sign:-Thickened zone of provisional
calcification
Cartilage proliferation is seen at epiphyseal end of
long bones
24. • 4.Corner’s sign: a groove is present just above
ZONE OF PROVISIONAL CALCIFICATION.
5.Trummer feld zone:fragmented metaphysis
6.Scurvy line :area in between zone of provisional
calcification and trummer feld zone.
7.Subperosteal hemorrhage
8.GROUND GLASS APPEARANCE OF SHAFT.
9.THINNING OF CORTEX IS PRESENT.