title: Effect of selenium status and supplementation with high-selenium yeast on plasma homocysteine and B vitamin concentrations in the UK elderly.
abstract: The level of plasma total homocysteine (tHcy), long known to be B vitamin dependent, has recently been shown to be inversely associated with plasma selenium (Se) concentration in human subjects. We therefore, chose to investigate the interaction between Se, tHcy and B vitamins in a double-blind, placebo-controlled trial where 501 healthy UK elderly volunteers were randomly allocated to receive 100, 200, or 300 microg Se/day as high-Se-yeast, or placebo-yeast for 6 months. Plasma Se, tHcy, folate, vitamin B-12, pyridoxal-5'-phosphate (PLP) and its catabolite, 4-pyridoxic acid, were measured in all participants at baseline and in samples from the placebo, 100 and 300 microg Se/day groups, at follow-up. At baseline, Se was inversely correlated with tHcy but only in males (p < 0.001). Before supplementation, tHcy concentration was significantly lower in the highest compared to the lowest Se tertile in males (p < 0.05), and in females when folate concentrations were also in the top tertile (p < 0.05). The effect of folate, PLP and vitamin B-12 concentrations on plasma tHcy correlated with Se concentration at baseline. After 6 months of Se supplementation, only Se concentration had changed significantly. Supplementation with Se does not affect tHcy concentration in the UK elderly population.
authors.affiliation: Division of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK.
authors.forename: Bram
authors.initials: B
authors.lastname: Bekaert
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Cooper
authors.forename: Fiona R
authors.initials: FR
authors.lastname: Green
authors.forename: Helene
authors.initials: H
authors.lastname: McNulty
authors.forename: Kristina
authors.initials: K
authors.lastname: Pentieva
authors.forename: John M
authors.initials: JM
authors.lastname: Scott
authors.forename: Anne M
authors.initials: AM
authors.lastname: Molloy
authors.forename: Margaret P
authors.initials: MP
authors.lastname: Rayman
mesh_terms: D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000378:metabolism; D000368:Aged; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005492:Folic Acid / Q000494:pharmacology; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D010919:Placebos; D012643:Selenium / Q000494:pharmacology* / Q000502:physiology*; D006113:United Kingdom; D014803:Vitamin B Complex / Q000097:blood*
chemical_list: D010919:Placebos; D006710:Homocysteine; D014803:Vitamin B Complex; D005492:Folic Acid; D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase; D012643:Selenium