This document summarizes a presentation about the importance of vitamin C in metabolic reactions. It discusses the structure of vitamin C, its daily recommended intake, dietary sources like citrus fruits and peppers, and key functions like aiding collagen formation and serving as an antioxidant. It also covers vitamin C's roles in defending against cancer and heart disease by protecting against oxidative damage. Deficiency results in scurvy due to impaired collagen synthesis. The presentation concludes that vitamin C plays an essential role in daily metabolic reactions in living organisms.

1. BABCOCK UNIVERSITY
COLLEGE OF HEALTH AND MEDICAL SCIENCES
BENJAMIN S. CARSON SCHOOL OF MEDICINE
DEPARTMENT OF BIOCHEMISTRY
2014/2015 ORAL SEMINAR PRESENTATION (BCHM 433)
IMPORTANCE OF VITAMIN C IN METABOLIC REACTIONS
BY
OYEWOLE ABIOLA OLATOMIDE
(11/0879)
BIOCHEMISTRY
400L
SUPERVISOR: PROF. O. OSILESI.

2. Introduction
 Vitamin C was first discovered during the search
for the cause of scurvy. Thus, the scientific name
‘ascorbic acid’ was coined out from the disease.
 It was later isolated by Hungarian scientist Szent-
Gyorgyi in 1928.
 Since then, various biomedical applications and
uses of vitamin c has been discovered with the
help of scientific research.

3. Biochemistry and Functions of Vitamin C
 Vitamin C which is also known as Ascorbic
acid is an essential water soluble vitamin
that is very important to human health.
 It has various important functions which it
performs in the metabolic reactions that
take place in living organisms.

4. Structure L-ascorbic acid.
(Iqbal et al., 2004)

5. Vitamin c Nutrition
 The Required Daily Allowance of
Vitamin C is a minimum of 90 milligrams
and no more than 2000 milligrams (2
grams) per day (Enstrom, 2005).

6. Biochemistry and Function of Vitamin C
(contd)
 Why is vitamin C essential to humans?
 Vitamin C is considered essential to
humans because we lack the enzyme ‘L-gulonolactone
oxidase’ which is required
for the synthesis of L-ascorbic acid from D-glucose.
(Iqbal et al., 2004)

7. Dietary Sources of vitamin c
 Vitamin c can be obtained majorly from
a wide range of fruit and vegetables like;
 Rose hip, Citrus fruit, Green peppers,
Red pepper, Broccoli, Brussels sprouts,
Turnips and other leafy vegetables.
 Milk and Fish also contain a
considerable amount of vitamin c
(Proteggente, 2009)

8. Dietary sources of vitamin c
(Nutrient data Laboratory, 2010)

9. Functions of Ascorbic acid
 The functions of Ascorbic acid in the living system
includes:
 Aiding in the formation of Collagen.
 It serves as an antioxidant in the cells.
 Defence Against Cancer
 Plays key role in the metabolism of cholesterol to
bile acids which helps in defence against heart
disease (Olson et al.,2012)

10. Ascorbic acid as an Antioxidant
 Ascorbic acid is useful in the cellular
environment because it helps to mop up free
radicals that can cause oxidative damage to
the cells.
 Ascorbic acid does this by donating electrons
to the unstable specie (element) in the cellular
environment. (Thurnham, 2000).

11. Antioxidant Action of Ascorbic
Acid
 Simple illustration of antioxidant mechanism
[Ascorbic acid]

12. Antioxidant Action of Ascorbic
Acid
(www.qiagen.com, 2012)

13. Regeneration of vitamin E
 Another important function that Ascorbic acid
plays in human health is the ‘Regeneration of
Vitamin E’
 Vitamin C helps to regenerate vitamin E from
vitamin E radical.
 Vitamin E radical is formed as a result of
vitamin E antioxidant action on lipid peroxyl
radical. (Myllyla et al, 2001)

14. Defence Against Cancer
 Cancers occur when cellular DNA is
damaged, causing mutations.
 Sometimes this damage is caused by free-radical
attacks.
 Antioxidants may reduce cancer risk by
protecting DNA from oxidative damage.
 Many studies report lower cancer rates
among people who consume abundant
fruits and vegetables rich in antioxidants
(Myllyla et al, 2001)

15. Defence Against Cancer
 Diets rich in vitamin C correlated with
lower cancer rates, especially cancer of
the mouth, larynx, esophagus, and
stomach.
 Such correlations reflect the benefit of
consuming a diet rich in fruits and
vegetables and low in fat, but it does not
necessarily support taking vitamin C
supplements to treat or prevent cancer.

16. Defence Against Heart Disease
 High LDL cholesterol is a major risk
factor for cardiovascular disease.
 One way LDL cholesterol increases the
risk of cardiovascular disease is that
free radicals in the arteries oxidize LDL
cholesterol. (Rath, 2006).
 Oxidized LDL cholesterol accelerates
the formation of artery-clogging plaques.

17. Defence Against Heart Disease
 Free radicals also oxidize
polyunsaturated fatty acids in cell
membranes, initiating additional
changes in artery walls which decrease
blood flow.
 Oxidative damage in artery walls is
increased by a diet high in saturated fat
or cigarette smoke.

18. Defence Against Heart Disease
 On the other hand, diets high in fruits
and vegetables, especially in
combination with unsaturated fat,
increase antioxidant action against LDL
cholesterol oxidation which can help
decreases the development of
atherosclerosis.

19. Deficiency of Vitamin C
 The main disease condition that results
as a result of vitamin C deficiency is
“scurvy”
 Due to the importance of ascorbic acid
in collagen synthesis, deficiency of
vitamin c results in poor tissue and bone
formation thus leading to scurvy.
(Enstrom, 2005).

20. Deficiency of Vitamin C
 An image depicting a severe case of
scurvy.

21. Conclusion
 In conclusion, we can see that vitamin c
plays a very important role in the daily
metabolic reactions that take place on
the molecular level. Thus making it very
essential for existence of life.

22. References
Enstrom E.J, 2005. Vitamin c intake and mortality among a sample of the united
states population, Epidemology, Pp:194-202.
Khalid Iqbal, Alam Khan, and M. Muzaffar Ali Khan Khattak 2004. Dietary
Sources and Metabolism, Biological Significance of Ascorbic Acid to Human Health.
Myllyla, R., Majamaa, K., Gunzler, V., Hanauske-Abal, H.M., Kivirikko, K.I,
2001.“Ascorbate is consumed stoichiometrically in the uncoupled reactions catalyzed by prolyl-
4-hydroxylase and lysyl hydroxylase” Journal of Biological Chemistry, Pp:213-275
Nutrient data Laboratory 2010. National Nutrient Database for Standard
Reference, Release 23. United States Department of Agriculture Research Service. Retreived
on 24-10-2014
Olson J.A, and Hodges R.E, 2012. Recommended Dietary Intake of vitamin c.
American Journal of Clinical Nutrition. Volume 53: 693-703
Platt B.S, Eddy T.P, and Pellet P.L, 1993. Nutritional Analysis of Food in Hospitals.
Nuffield Provincial Hospitals Trust and Oxford University, London.
Thurnham D.I, 2000. Water Soluble vitamins (Vitamin C and B vitamins, Thiamin,
Riboflavin, and Niacin), Journal of Nutrition and Dietetics. Pp:231-244
Proteggente, A.R., Rehman, A., Halliwell, B., Rice-Evans, C.A, 2009. “Potential
problems of ascorbate and iron supplementation: pro-oxidant effect in vivo?” Journal of
Biochemical Physiology. Pp:277-286

23. Thank You
for
Listening.