VITAMIN C

1. VITAMIN C
Dr. Muhammad Sarfraz
M.B.B.S., M.Phil.(Pharmacology)
Senior Demonstrator
Quaid-e-Azam Medical College
Bahawalpur, pakistan.
1

2. Vitamin C
L-ASCORBIC ACID
2

3. VITAMIN C
Ascorbic Acid
• Vitamin For Humans And Other
Primates
• Summary formula C6H8O6
• The bioactive form of vitamin C is
only the L-form
• NATURAL SOURCES OF VITAMIN
C CONTAIN ONLY THE L-
FORM 3

4. VITAMIN C
Ascorbic Acid
Vitamin C is destroyed
by
OXYGEN
HEAT( > 70°C)
LIGHT
FREEZING
AND
REDUCTANTS 4

5. VITAMIN C
• IT IS WATER SOLUBLE
VITAMIN.
• VIT.C IS A STRONG
REDUCING AGENT IN AQ.
PHASE OF LIVING TISSUES
• EASILY AND REVERSIBLY
OXIDISED TO
DEHYDROASCORBIC ACID

6. VITAMIN C
• IT ACTS AS ANTI-OXIDANT.
• VIT.C IS NECESSARY FOR A
NUMBER OF METABOLIC
PROCESS INCLUDING
“H” ION TRANSFER

7. VITAMIN C
• FACILITATES UPTAKE OF
IRON IN INTESTINAL TRACT
• INVOLVED IN FORMATION OF
ACTIVE FORM OF FOLIC ACID
(FOLINIC ACID)

8. VITAMIN C
Highly Concentrated
In
Pituatary
Adrenals
Eyes
Platelets
And
WBCs

9. Vitamin C
9

10. Scurvy Killed More Sailors Than
Were Lost In All Sea Battles.
10

11. Four Species Lack
The Enzymes For
Vitamen C
Synthesis

12. CAPYBARA
12

13. PRIMATES

14. GIINEA PIG

15. BAT

16. Why is vitamin ‘C’ VITAMIN for man?
Man
One Of The Four
Known Mammalian Species
Who Cannot Produce Own
Vitamin C
So Became A Vitamin For Us
16

17. Why is vitamin ‘C’ VITAMIN for man?
Should Be
Consumed Every Day
Because It Cannot Be Stored
For Later Use
• RDA = 60 Mg Vitamin C
17

18. MANY ANIMALS CAN
SYNTHESIZE ASCORBIC ACID
FROM GLUCOSE
VIA
URONIC ACID PATHWAY
Mammalians need the four enzymes to
make vitamin C.
18

19. We have the first three enzymes
MAN AND OTHER PRIMATES
CANNOT SYNTHESIZE VIT.C DUE
TO THE LACK OF SINGLE
ENZYME
• L-GLUCONOLACTONE
OXIDASE
19

20. 20

21. 21

22. Sources of Ascorbic acid
• Ascorbic Acid Is Widely
Distributed In
Fresh Fruits And Vegetables
Red Pepper
• Lychee, Papaya, Strawberry
Orange ,Lemon, Melon
22

23. Sources of Ascorbic acid
Cauliflower, Garlic,
Grapefruit, Spinach,
Cabbage MANGO, Potato,
Tomato, Pineapple, Grape,
Banana, Carrot,Apricot e.t.c.
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24. 24

25. RECOMMENDED DIETARY
ALLOWANCE (RDA)
• RECOMMENDED DIETARY
ALLOWANCE FOR VIT.C RANGES
FROM 35MG IN INFANTS TO
60MG IN ADULTS.
• PREGNANT AND LACTATING
WOMEN SHOULD INCREASE
THEIR INTAKE BY 20MG AND
40MG RESPECTIVELY

26. 26

27. Functions of vitamin C
• Synthesis Of Collagen
• The Main Protein Substance
Of The Human Body
• Makes Up The Structures
That Hold Our Bodies
Together, Such As
• Connective Tissues
• Cartilage Or Tendons
27

28. Functions of vitamin C
• PROLINE HYDROXYLASES
And
• LYSINE HYDROXYLASES
Are Required For The
Postsynthetic Modification
Of Procollagen To
Collagen 28

29. Functions of vitamin C
Vitamin C
Cofactor
For
Proline Hydroxylase
Lysine Hydroxylase
29

30. Functions of vitamin C
Inadequately
Hydroxylated Precursors
Cannot Acquire Stable
Helical Configuration And
Cannot Be Adequately
Crosslinked So They Are
Poorly Secreted From
Fibroblast.
30

31. Functions of vitamin C
• THE SECRETED FIBRES
LACK TENSILE STRENGTH,
ARE MORE SOLUBLE
AND MORE VULNERABLE
TO ENZYMATIC
DEGRADATION.
31

32. Functions of vitamin C
•LACK OF VIT.C
LEADS TO
SUPRESSION OF THE
RATE OF SYNTHESIS
OF PRO-COLLAGEN
PEPTIDES
32

33. Functions of vitamin C
• COLLAGEN
( CONTAINS HIGHEST AMOUNT
OF HYDROXYPROLINE)
MOSTLY AFFECTED
PARTICULARLY IN BLOOD
VESSELS LEADING TO
HAEMORRHAGES IN SCURVY
33

34. Functions of vitamin C
•Essential For
Wound Repair
And
Healthy Gums
•Important Role In All
Immune System
Functions. 34

35. Functions of vitamin C
•Proline
Hydroxylase
Required In
Formation Of The
C1q Component Of
Complement
35

36. Functions of vitamin C
Proline Hydroxylase
Required In
Formation Of
Osteocalcin
36

37. Functions of vitamin C
• Vitamin C Is Required
For
Synthesis Of
Dopamine
Noradrenaline
And
Adrenaline
In The Nervous System.
37

38. 38

39. Functions of vitamin C
Vitamin C Is Also
Needed To
Synthesise Carnitine
Important In The
Transfer Of Energy To
The Cell Mitochondria
39

40. 40

41. Functions of vitamin C
Vitamin C Also
Facilitates The Absorption Of
Dietary Iron
From The Intestine and this
depends on the presence of
the vitamin C in the gut
BY KEEPING IT IN
FERROUS FORM WHICH IS
DUE TO REDUCING
PROPERTY OF VIT.C. 41

42. 42

43. 43

44. Functions of vitamin C
• Highly Effective
ANTIOXIDANT
ABSORBS FREE OXYGEN
RADICALS
44

45. 45

46. Functions of vitamin C
Protect Indispensable
Molecules In The Body
Such As
PROTEINS, LIPIDS,
CARBOHYDRATES, AND
NUCLEIC ACIDS
(DNA And RNA)
From Damage By Free
Radicals 46

47. 47

48. 48

49. 49

50. •Osteocalcin
•Carnitine
•C1q
50

51. 51

52. Deficiency of ascorbic acid
SCURVY
• Defective Collagen
SYNTHESIS
Impairs Wound Healing
• Collagen Is Also An
Important Part Of Bone
So Bone Formation Is
Also Affected. 52

53. Deficiency of ascorbic acid
SCURVY
Tooth Loss
Bone Fractures
• Defective Connective Tissue Also
Leads To
• Fragile Capillaries
• Resulting In
Abnormal Bleeding
Gum Decay
• Defective Immunity 53

54. 54

56. Deficiency of ascorbic acid
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58. 58