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Ascorbic acid - Vitamin C
Specifications
Definition
Water soluble vitamin
Chemical name: 2-oxo-L-threo-hexono-1,4-lactone-2,3-enediol
A six-carbon compound, structurally related to glucose
Characteristics
Average half life: 10-20 days
2
Elimination via the urine
Renal threshold: plasma ascorbate concentrations of about 1.2-1.8 mg/dL
corresponding to 60 mg doses per day
3-6
Average body tissue of an adult stores 1.2-2.0 g presumably maintained by taking 60-75 mg per day
3-5 ,7,8
RDA*
90 mg per day for an adult male (set by the US Food and Nutrition Board in 2000)
9
Ingestion of 60 mg/day prevents the development of scurvy for 30-45 days with a diet lacking vitamin C
3,4 ,7,8
Sources
Natural: fresh fruits and vegetables, e.g., oranges, lemons, grapefruits, watermelons, papayas, strawberries,
green leafy vegetables, tomatoes, broccoli, etc.
Synthetic: used in vitamin preparation, as preservative and antioxidant (e.g., E300, E301, E302, E303, E304),
discoloration inhibitor, supplement in tablets, food additive
Consumption
The most frequently used vitamin supplement in the world
10
Worldwide annual demand in 1995 was evaluated at 60.000 tons
11
Functions
Required for many metabolic functions in humans and cofactor for lots of metabolic reactions
Potent reducing agent playing an important role in the antioxidant defense system, immune competence, and
in strengthening resistance to infection
Vitamin C prevents DNA mutations and might be important in treating certain cancers, heart disease and
other chronic diseases
Interference
Ascorbic acid has the ability to prevent oxidization of indicator substances in urine test strips e.g. in peroxidase
redox indicator test principle. Interference can be removed using iodate test components such as applied in
Combur-Test
®
* Recommended daily allowance
References
1. Nagel, D., Seiler, D., Hohenberger, E.F., Ziegler, M. (2006). Investigations of ascorbic acid interference in urine test strips. Clin Lab; 52:149-153.
2. Hellman, L., Burns, J.J. (1958). Metabolism of L-ascorbic acid-1-C14 in man. J Biol Chem; 230:923-930.
3. Baker, E.M., Hodges, R.E., Hood, J., Sauberlich, H.E., March, S.C. (1969). Metabolism of ascorbic-1-14C acid in experimental human scurvy. Am J Clin Nutr; 22:549-558.
4. Baker, E.M., Hodges, R.E., Hood, J., Sauberlich, H.E., March, S.C., Canham, J.E. (1971). Metabolism of 14C- and 3H-labeled L-ascorbic acid in human scurvy. Am J Clin Nutr; 24:444-454.
5. Kallner, A., Hartmann, D., Hornig, D. (1979). Steady-state turnover and body pool of ascorbic acid in man. Am J Clin Nutr; 32:530-539.
6. Pietrzik, K., Loew, D., Golly, I. (2008). Vitamin C. In: Handbuch Vitamine. Für Prophylaxe, Therapie und Beratung. Munich: Urban & Fischer, Elsevier GmbH; 173-185.
7. Hodges, R.E., Baker, E.M., Hood, J., Sauberlich, H.E., March, S.C. (1969). Experimental scurvy in man. Am J Clin Nutr; 22:535-548.
8. Hodges, R.E., Hood, J., Canham, J.E., Sauberlich, H.E., Baker, E.M. (1971). Clinical manifestations of ascorbic acid deficiency in man. Am J Clin Nutr; 24:432-443.
9. Food and Nutrition Board IoM, National Academies. (2008). Dietary Reference Intakes: Recommended Intakes for Individuals, Vitamins. Washington D.C.
10. Naidu, K.A. (2003). Vitamin C in human health and disease is still a mystery? An overview. Nutr J; 2: 7.
11. Elvers, B., Hawkinds, S. (1996). Ullmann’s Encyclopedia of Industrial Chemistry.