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- Eussen, Simone J. P. M., et al.
(författare)
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North-south gradients in plasma concentrations of B-vitamins and other components of one-carbon metabolism in Western Europe: results from the European Prospective Investigation into Cancer and Nutrition (EPIC) Study
- 2013
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Ingår i: British Journal of Nutrition. - 1475-2662 .- 0007-1145. ; 110:2, s. 363-374
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Tidskriftsartikel (refereegranskat)abstract
- Different lifestyle patterns across Europe may influence plasma concentrations of B-vitamins and one-carbon metabolites and their relation to chronic disease. Comparison of published data on one-carbon metabolites in Western European regions is difficult due to differences in sampling procedures and analytical methods between studies. The present study aimed, to compare plasma concentrations of one-carbon metabolites in Western European regions with one laboratory performing all biochemical analyses. We performed the present study in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort among 5446 presumptively healthy individuals. Quantile regression was used to compare sex-specific median concentrations between Northern (Denmark and Sweden), Central (France, Germany, The Netherlands and United Kingdom) and Southern (Greece, Spain and Italy) European regions. The lowest folate concentrations were observed in Northern Europe (men, 10.4 nmol/l; women, 10.7 nmol/l) and highest concentrations in Central Europe. Cobalamin concentrations were slightly higher in Northern Europe (men, 330 pmol/l; women, 352 pmol/l) compared with Central and Southern Europe, but did not show a clear north-south gradient. Vitamin B-2 concentrations were highest in Northern Europe (men, 22.2 nmol/l; women, 26.0 nmol/l) and decreased towards Southern Europe (P-trend < 0.001). Vitamin B-6 concentrations were highest in Central Europe in men (77.3 nmol/l) and highest in the North among women (70.4 nmol/l), with decreasing concentrations towards Southern Europe in women (P-trend < 0.001). In men, concentrations of serine, glycine and sarcosine increased from the north to south. In women, sarcosine increased from Northern to Southern Europe. These findings may provide relevant information for the study of regional differences of chronic disease incidence in association with lifestyle.
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| 3. |
- Midttun, Öivind, et al.
(författare)
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Plasma vitamin B-6 forms and their relation to transsulfuration metabolites in a large, population-based study
- 2007
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Ingår i: American Journal of Clinical Nutrition. - Bethesda : American society for nutrition. - 0002-9165 .- 1938-3207. ; 86:1, s. 131-138
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Tidskriftsartikel (refereegranskat)abstract
- Background: Vitamin B-6 exists in different forms; one of those forms, pyridoxal 5'-phosphate (PLP), serves a cofactor in many enzyme reactions, including the transsulfuration pathway, in which homocysteine is converted to cystathionine and then to cysteine. Data on the relations between indexes of vitamin B-6 status and transsulfuration metabolites in plasma are sparse and conflicting.Objective: We investigated the distribution and associations of various vitamin B-6 species in plasma and their relation to plasma concentrations of transsulfuration metabolites.Design: Nonfasting blood samples from 10 601 healthy subjects with a mean age of 56.4 y were analyzed for all known vitamin B-6 vitamers, folate, cobalamin, riboflavin, total homocysteine, cystathionine, total cysteine, methionine, and creatinine. All subjects were genotyped for the methylenetetrahydrofolate reductase (MTHFR) 677C -> T polymorphism.Results: Plasma concentrations of the main vitamin B-6 vitamers-PLP, pyridoxal, and 4-pyridoxic acid-were strongly correlated. Among the vitamin B-6 vitamers, PLP showed the strongest and most consistent inverse relation to total homocysteine and cystathionine, but the dose response was different for the 2 metabolites. The PLP-total homocysteine relation was significant only in the lowest quartile of the vitamin B-6 distribution and was strongest in subjects with the MTHFR 677TT genotype, whereas cystathionine showed a graded response throughout the range of vitamin B-6 vitamer concentrations, and the effect was not modified by the MTHFR 677C -> T genotype.Conclusion: This large population-based study provided precise estimates of the relation between plasma concentrations of vitamin B-6 forms and transsulfuration metabolites as modified by the MTHFR 677C -> T genotype.
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