Adaptation of Coenzyme Stimulation Assays for the Nutritional Assessment of Vitamins B1, B2 and B6 Using the Cobas Bio Centrifugal Analyser

Mount, J N; Heduan, E; Herd, C. W.; Jupp, R A; Kearney, E.

doi:10.1177/000456328702400106

Cited by 39 publications

(17 citation statements)

References 8 publications

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“…Enzymatic methods are affected by preparation of hemolysates (8) and by storage (5,52) and concentrations of substrates and cofactors (35). These factors lead to a notable analytical variation between laboratories.…”

Section: Methodological Issuesmentioning

confidence: 99%

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Indicators of Vitamin and Mineral Status in Athletes' Blood: A Review

Fogelholm¹

1995

International Journal of Sport Nutrition

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This review examines the hypothesis that vitamin and mineral status in athletes is inadequate for optimal sports performance. The review is based on indicators determined from blood and on studies published since 1980. Most of the studies did not find micronutrient status in athletes to be different from untrained controls. The serum fenitin concentration in females was lower than in males (27 vs. 78 yg . L-I), and the prevalence of low serum ferritin concentration was higher in female athletes than in untrained female controls (37 vs. 23%). Supplementation of water-soluble vitamins and iron was associated with an improvement in the corresponding indicators. Excluding a few studies with mildly anemic subjects, improvements in indicators of micronutrient status were not associated with enhanced athletic performance. Consequently, the levels of indicators of micronutrient status seen in athletes' blood were apparently compatible with optimal physical performance.

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Section: Methodological Issuesmentioning

confidence: 99%

“…The corresponding values for E-GRAC were 1.20 (31) and 1.68 (52) and for 5ASTAC 1.80 (82) and 2.47 (27). Ideally, each laboratory should make its own reference interval or should ascertain that the chosen reference interval is made by precisely comparable methods.…”

Section: Methodological Issuesmentioning

confidence: 99%

Indicators of Vitamin and Mineral Status in Athletes' Blood: A Review

Fogelholm¹

1995

International Journal of Sport Nutrition

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“…Measurement of EASTAC (Mount et al, 1987) and EGRAC (Powers et al, 1983) were by enzyme assay on the Cobas Fara centrifugal analyzer (Roche Diagnostics, Welwyn Garden City, UK). For all assays, samples were analysed blind, in duplicate (except for EGRAC where triplicate samples were measured), and within 6 months after sampling.…”

Section: Laboratory Measurementsmentioning

confidence: 99%

Effect of riboflavin supplementation on plasma homocysteine in elderly people with low riboflavin status

et al. 2002

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Objective: To investigate the effect of riboflavin supplementation on plasma homocysteine (tHcy) concentrations in healthy elderly people with sub-optimal riboflavin status. Design: A double-blind, randomized, placebo-controlled riboflavin supplementation trial. Setting: Community based study in Northern Ireland. Subjects: From a screening sample of 101 healthy elderly people, 52 had sub-optimal riboflavin status (erythrocyte glutathione reductase activation coefficient, EGRAC ! 1.20) and were invited to participate in the study. Intervention: The intervention had two parts. Part 1 was a 12 week randomized double blind, placebo-controlled intervention with riboflavin (1.6 mg=day). Following completion of part 1, the placebo group went on to part 2 of the study which involved supplementation with folic acid (400 mg=day) for 6 weeks followed by folic acid and riboflavin (1.6 mg=day) for a further 12 weeks, with a 16 week washout period post-supplementation. The purpose of part 2 was: (a) to address the possibility that homocysteine-lowering in response to riboflavin may be obscured by a much greater effect of folate, and that, once folate status was optimized, a dependence of homocysteine on riboflavin might emerge; and (b) to demonstrate that these subjects had homocysteine concentrations which could be lowered by nutritional intervention. Results: Although riboflavin supplementation significantly improved riboflavin status in both parts 1 and 2 of the study (P < 0.001 for each), tHcy concentrations were unaffected (P ¼ 0.719). In contrast, folic acid supplementation (study part 2) resulted in a homocysteine lowering of 19.6% (P ¼ 0.001). Conclusion: Despite the metabolic dependency of tHcy on riboflavin, it did not prove to be an effective homocysteine-lowering agent, even in the face of sub-optimal riboflavin status.

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“…Plasma total homocysteine was measured by Abbott Imx FPIA (Leino, 1999). Erythrocyte aspartate aminotransferase activation coefficient (index of vitamin B 6 status) and erythrocyte glutathione reductase activation coefficient (index of riboflavin status) were measured by enzyme assay on the Cobas Fara centrifugal analyser (Roche Diagnostics, Welwyn Garden City, UK) according to the procedure of Mount et al (1987). Plasma pyridoxal phosphate was determined by HPLC using fluorescent detection (Bates et al, 1999).…”

Section: Methodsmentioning

confidence: 99%

Acute absorption of folic acid from a fortified low-fat spread

et al. 2003

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Objective: To explore the feasibility of low-fat spreads as vehicles for folic acid (FA) fortification by determining the acute absorption of FA from a fortified spread. Design: Double blind, crossover study to test each of the following treatments administered at 1-weekly intervals: (A) 20 g lowfat (40%) spread fortified with 200 mg FA and a placebo tablet; (B) 20 g low-fat placebo spread and a 200 mg FA tablet; (C) 20 g low-fat placebo spread and a placebo tablet. Subjects: A total of 13 male volunteers, aged 31.8713.2 y. Main outcome measures: Plasma total folate concentrations, measured before and up to 10 h after each treatment (n ¼ 10 samples per treatment). Results: Plasma folate concentrations were significantly increased compared with baseline values 1 h after administration of the FA tablet, and 1.5 h after the FA spread, and remained significantly higher than the baseline values for up to 7 h after both treatments. The maximum plasma folate response (R max ), corrected for baseline values and 'placebo response', was established between 1 and 3 h postprandially in response to both FA spread and FA tablet, and no significant difference in R max was found between the two treatments (13.4 vs 14.4 nmol/l, P ¼ 0.9). The acute absorption of FA from fortified spread relative to that from the tablet, calculated on the basis of area under the plasma folate response curve, was 67% (P ¼ 0.04). Conclusion: The absorption of FA from fortified low-fat spread, although lower than from a tablet, is effective. These results suggest that low-fat spreads, typically associated with fat-soluble vitamin fortification, may also be considered feasible as vehicles for FA fortification.

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Adaptation of Coenzyme Stimulation Assays for the Nutritional Assessment of Vitamins B1, B2 and B6 Using the Cobas Bio Centrifugal Analyser

Cited by 39 publications

References 8 publications

Indicators of Vitamin and Mineral Status in Athletes' Blood: A Review

Indicators of Vitamin and Mineral Status in Athletes' Blood: A Review

Effect of riboflavin supplementation on plasma homocysteine in elderly people with low riboflavin status

Acute absorption of folic acid from a fortified low-fat spread

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