H J Powers

..Recent National Diet and Nutrition Surveys in the United Kingdom have shown that young women in particular are at risk of moderate riboflavin deficiency and low iron status...

..Few published trials include such information and the number of participants screened or approached is not always cited...

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..It is concluded that whilst there are several biochemical measures which respond to changes in intake of each of these vitamins, no single measure is wholly satisfactory as a marker of optimum status...

..Colorectal mucosal folate concentration responds to folic acid supplementation to an extent comparable to that seen in plasma, but with a suggestion of an upper limit...

..An additional factor determining the effect of diet and genotype interactions on cancer risk may be the stage of cancer development...

..Moderate riboflavin deficiency is prevalent in certain population groups in affluent countries, but the functional significance of this deficiency is not clear. Studies have indicated a role for riboflavin in the absorption and use of iron...

..Immunoassays and high-performance liquid chromatography methods are currently available in kit form, fluorescence polarization immunoassay showing the best performance...

..Riboflavin deficiency may exert some of its effects by reducing the metabolism of other B vitamins, notably folate and vitamin B-6...

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..CONCLUSIONS: In healthy individuals lowering plasma tHcy does not have any functional implications regarding oxidative damage...

..Thus hyperhomocysteinaemia may pose an oxidative stress not only through the direct cytotoxicity of homocysteine, but also from an associated fall in plasma cysteine...

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..The details of the EGRAC method should be standardised for use in different laboratories and over time. Additionally, it is proposed that consideration be given to re-evaluating the basis of the EGRAC threshold for riboflavin deficiency...

..Methods have been developed for the rapid measurement of lymphocyte and buccal mucosal total folate. Lymphocyte folate is sensitive to folate intake and is reflected by plasma 5-MeTHF...

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..CONCLUSIONS: Antioxidants supplementation with or without B-group vitamins enhances antioxidant capacity, mitigates oxidative damage, and may have an anti-inflammatory effect immediately postinfarct in stroke disease...

..05). These findings are compatible with a role for folate in modulating the risk of cervical cancer, possibly through an influence over high-risk HPV infection. DAPK, CDH1, and HIC1 genes are potential biomarkers of cervical cancer risk...

..This study aims to establish whether riboflavin deficiency has consequences for gastrointestinal (GI) morphology in adults and what the effects and effectors of any such alteration may be...

..SPONSORSHIP: Sheffield Teaching Hospital NHS Trust...

..The authors studied the link between tHcy and IBD in children, in whom associations may be clearer, and investigated associations with plasma von Willebrand factor antigen, a marker of vascular damage...

..Because G6PD deficiency is common in parts of the world where ariboflavinosis is endemic, it is important to have a measure of riboflavin status that is unaffected by differences in G6PD status...

..05). In conclusion, B-group vitamin supplementation immediately post-infarct may have antioxidant and anti-inflammatory effects in stroke disease independent of a homocysteine-lowering effect...

..The absence of riboflavin in the duodenal lumen impairs normal development, suggesting that a crypt sensing mechanism may be involved in the response to riboflavin deficiency...

..Factors that regulate intracellular Hcy metabolism modulate these effects...

..The likely role of homocysteine in LDL oxidation in vivo is discussed in the light of these results...

..The formation of the rupture initiation site is a function of a regional variation in collagen cross-link ratio. Tissue ascorbic acid status may be an important mediator of these processes...

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..Low folate status and elevated plasma homocysteine are associated with increased risk of neural tube defects and cardiovascular disease. Homocysteine responses to folate may be influenced by genetic variants in folate metabolism...

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..It has been proposed that riboflavin may act together with folate to lower plasma tHcy, particularly in individuals with the thermolabile MTHFR T variant...

..One reason for this may be an overestimate of the bioavailability of riboflavin from foods, about which relatively little is known...

..The present studies suggest that elevated plasma tHcy may promote LDL nitration and increased scavenger receptor uptake, providing a molecular mechanism that may contribute to the clinical link between CVD and elevated plasma tHcy...