title: Assessment of lutein, zeaxanthin andmeso-zeaxanthin concentrations in dietary supplements by chiral high-performance liquid chromatography.
abstract: We investigated the concordance between actual and declared content of the three macular carotenoids in commercially available supplements aimed at eye health. Three batches of nine products were tested for content of lutein (L), zeaxanthin (Z) andmeso-zeaxanthin (MZ) by chiral HPLC-DAD. In every product tested, actual L concentration was close to target, but Z concentration varied greatly (47-248 % of declared concentration), and the L:Z ratio within some supplements was adversely affected in consequence. In six of seven products not declaring MZ, we found this carotenoid, and four of them, using the same L source, contained a concentration of MZ that correlated positively and significantly with measured concentrations of L (r2= 0.86;P< 0.001). More transparency is needed in terms of concordance between actual and declared concentrations of Z in commercially available formulations, and MZ should be declared in those formulations where it is present.
authors.affiliation: Macular Pigment Research Group, Vision Research Centre, Department of Chemical and Life Sciences, Waterford Institute of Technology, Carriganore House, Waterford, Ireland.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Prado-Cabrero
authors.affiliation: Macular Pigment Research Group, Vision Research Centre, Department of Chemical and Life Sciences, Waterford Institute of Technology, Carriganore House, Waterford, Ireland.
authors.forename: Stephen
authors.initials: S
authors.lastname: Beatty
authors.affiliation: Downing College, The Howard Foundation, University of Cambridge, Cambridge, UK.
authors.forename: Alan
authors.initials: A
authors.lastname: Howard
authors.affiliation: Macular Pigment Research Group, Vision Research Centre, Department of Chemical and Life Sciences, Waterford Institute of Technology, Carriganore House, Waterford, Ireland.
authors.forename: Jim
authors.initials: J
authors.lastname: Stack
authors.affiliation: Institute of Pharmaceutical Biology, University of Greifswald, Greifswald, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Bettin
authors.affiliation: Macular Pigment Research Group, Vision Research Centre, Department of Chemical and Life Sciences, Waterford Institute of Technology, Carriganore House, Waterford, Ireland.
authors.forename: John M
authors.initials: JM
authors.lastname: Nolan
keywords: Chiral HPLC–DAD; Lutein; Macula; Zeaxanthin; meso-zeaxanthin