Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-23T15:59:09.936Z Has data issue: false hasContentIssue false

The ‘anomalous’ absorption of labelled and unlabelled vitamin C in man

Published online by Cambridge University Press:  08 March 2007

Leslie J. C. Bluck*
Affiliation:
MRC Human Nutrition Research, Fulbourn Road, Cambridge, CB1 9NL, UK
Kerry S. Jones
Affiliation:
MRC Human Nutrition Research, Fulbourn Road, Cambridge, CB1 9NL, UK
W. Andy Coward
Affiliation:
MRC Human Nutrition Research, Fulbourn Road, Cambridge, CB1 9NL, UK
Christopher J. Bates
Affiliation:
MRC Human Nutrition Research, Fulbourn Road, Cambridge, CB1 9NL, UK
*
*Corresponding author: Dr Les Bluck, fax +44 (0) 1223 437515, email [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Previous studies of vitamin C absorption in man using stable isotope probes have given results which cannot easily be reconciled with those obtained using non-isotope measurement. In order to investigate some of the apparent paradoxes we have conducted a study using two consecutive doses of vitamin C, one labelled and one unlabelled, given 90 min apart. Compatibility of the experimental results with two feasible models was investigated. In Model 1, ingested vitamin C enters a pre-existing pool before absorption, which occurs only when a threshold is exceeded; in Model 2, ingested vitamin C is exchanged with a pre-existing flux before absorption. The key difference between these two models lies in the predicted profile of labelled material in plasma. Model 1 predicts that the second unlabelled dose will produce a secondary release of labelled vitamin C which will not be observed on the basis of Model 2. In all subjects Model 1 failed to predict the observed plasma concentration profiles for labelled and unlabelled vitamin C, but Model 2 fitted the experimental observations. We speculate on possible physiological explanations for this behaviour, but from the limited information available cannot unequivocally confirm the model structure by identifying the source of the supposed flux.

Type
Research Article
Copyright
Copyright © The Nutrition Society 2005

References

Baker, E, Hodges, R, Hood, J, Sauberlich, H, March, S & Canham, J (1971) Metabolism of 14 C and 3 H-labelled l -ascorbic acid in human scurvy. Am J Clin Nutr 24, 444454.CrossRefGoogle Scholar
Baker, EM, Hodges, RE, Hood, J, Sauberlich, HE & March, SC (1969) Metabolism of ascorbic-1- 14 C acid in experimental human scurvy. Am J Clin Nutr 22, 549558.CrossRefGoogle Scholar
Basu, TK & Schorah, CJ (1982) Vitamin C in Health and Disease. London: Croom Helm.Google Scholar
Bates, CJ (1997) Bioavailability of vitamin C. Eur J Clin Nutr 51, S28S33.Google ScholarPubMed
Bates, CJ, Jones, KS & Bluck, LJC (2004) Stable isotope-labelled vitamin C as a probe for vitamin C absorption by human subjects. Br J Nutr 91, 699705.CrossRefGoogle ScholarPubMed
Blanchard, J, Conrad, KA & Garry, PJ (1990a) Effects of age and intake on vitamin-C disposition in females. Eur J Clin Nutr 44, 447460.Google ScholarPubMed
Blanchard, J, Conrad, KA, Mead, RA & Garry, PJ (1990b) Vitamin-C disposition in young and elderly men. Am J Clin Nutr 51, 837845.CrossRefGoogle Scholar
Bluck, LJC, Izzard, AP & Bates, CJ (1996) Measurement of ascorbic-acid kinetics in man using stable isotopes and gas-chromatography mass-spectrometry. J Mass Spectrom 31, 741748.3.0.CO;2-H>CrossRefGoogle ScholarPubMed
Bluck, LJC, Jones, KS & Bates, CJ (2002) H-2- and C-13-labelled tracers compared for kinetic studies of ascorbic acid metabolism in man: a factor analytical approach. Rapid Commun Mass Spectrom 16, 879883.CrossRefGoogle Scholar
Davies, HEF, Davies, JEW, Hughes, RE & Jones, E (1984) Studies on the absorption of l -xyloascorbic acid (vitamin-C) in young and elderly subjects. Human Nutr-Clin Nutr 38, 463471.Google Scholar
Graumlich, JF, Ludden, TM, ConryCantilena, C, Cantilena, LR, Wang, YH & Levine, M (1997) Pharmacokinetic model of ascorbic acid in healthy male volunteers during depletion and repletion. Pharm Res 14, 11331139.CrossRefGoogle Scholar
Hornig, D (1975) Distribution of ascorbic acid, metabolites and analogues in men and animals. Ann N Y Acad Sci 54, 103118.CrossRefGoogle Scholar
Izzard, A, Bluck, LJC & Bates, C (1996) Measurement of stable isotope [ 13 C]ascorbate using gas chromatography with mass spectrometry. Proc Nutr Soc 55 Suppl.1A, 88A.Google Scholar
Jones, KS, Bluck, LJ, McLeod, G & Bates, CJ (2002) The rate of appearance and disappearance of ascorbate (vitamin C) in plasma of orally-dosed humans, studied by stable isotope probes. Free Radic Res 36, 3940.Google Scholar
Kallner, A, Hartmann, D & Hornig, D (1979) Steady-state turnover and body pool of ascorbic acid in man. Am J Clin Nutr 32, 530539.CrossRefGoogle ScholarPubMed
Kallner, AB, Hartmann, D & Hornig, DH (1981) On the requirements of ascorbic-acid in man – steady-state turnover and body pool in smokers. Am J Clin Nutr 34, 13471355.CrossRefGoogle ScholarPubMed
Levine, M, ConryCantilena, C, Wang, YH, Welch, RW, Washko, PW, Dhariwal, KR, Park, JB, Lazarev, A, Graumlich, JF, King, J & Cantilena, LR (1996) Vitamin C pharmacokinetics in healthy volunteers: evidence for a recommended dietary allowance. Proc Natl Acad Sci USA 93, 37043709.CrossRefGoogle ScholarPubMed
Liang, WJ, Johnson, D & Jarvis, SM (2001) Vitamin C transport systems of mammalian cells. Mol Membr Biol 18, 8795.CrossRefGoogle ScholarPubMed
Naidu, KA (2003) Vitamin C in human health and disease is still a mystery? An overview. Nutr J 2, 7.CrossRefGoogle Scholar
Piotrovskij, VK, Kallay, Z, Gajdos, M, Gerykova, M & Trnovec, T (1993) The use of a nonlinear absorption-model in the study of ascorbic-acid bioavailability in man. Biopharm Drug Dispos 14, 429442.CrossRefGoogle Scholar
Ruston, D, Hoare, J, Henderson, L, Gregory, J, Bates, CJ, Prentice, A, Birch, M, Swan, G & Farron, M (2004) The National Diet & Nutrition Survey: Adults Aged 19 to 64 Years. London: TSO.Google Scholar
Schorah, CJ (1992) The transport of vitamin-C and effects of disease. Proc Nutr Soc 51, 189198.CrossRefGoogle ScholarPubMed
Som, S, Basu, S, Mukherjee, D, Deb, S, Choudhury, PR, Mukherjee, S, Chatterjee, SN & Chatterjee, IB (1981) Ascorbic-acid metabolism in diabetes-mellitus. Metabolism 30, 572577.CrossRefGoogle ScholarPubMed
Wright, AJA, Finglas, PM, Dainty, JR, Hart, DJ, Wolfe, CA, Southon, S & Gregory, JF (2003) Single oral doses of C-13 forms of pteroylmonoglutamic acid and 5-formyltetrahydrofolic acid elicit differences in short-term kinetics of labelled and unlabelled folates in plasma: potential problems in interpretation of folate bioavailability studies. Br J Nutr 90, 363371.CrossRefGoogle Scholar