title: Effect of vitamin E intake from food and supplement sources on plasma α- and γ-tocopherol concentrations in a healthy Irish adult population.
abstract: Vitamin E is believed to play a preventive role in diseases associated with oxidative stress. The aims of the present study were to quantify vitamin E intake levels and plasma concentrations and to assess dietary vitamin E adequacy in Irish adults. Intake data from the National Adult Nutrition Survey were used; plasma samples were obtained from a representative cohort of survey participants. Plasma α- and γ-tocopherol concentrations were measured by HPLC. The main sources of vitamin E in the diet were 'butter, spreadable fats and oils' and 'vegetables and vegetable dishes'. When vitamin E intake from supplements was taken into account, supplements were found to be the main contributor, making a contribution of 29·2 % to vitamin E intake in the total population. Supplement consumers had significantly higher plasma α-tocopherol concentrations and lower plasma γ-tocopherol concentrations when compared with non-consumers. Consumers of 'vitamin E' supplements had significantly higher vitamin E intake levels and plasma α-tocopherol concentrations compared with consumers of other types of supplements, such as multivitamin and fish oil. Comparison with the Institute of Medicine Estimated Average Requirement of 12 mg/d indicated that when vitamin E intake from food and supplement sources was taken into account, 100 % of the study participants achieved the recommended intake levels. When vitamin E intake from food sources was taken into account, only 68·4 % of the females were found to achieve the recommended intake levels compared with 99·2 % of the males. The results of the present study show that dietary vitamin E intake has a significant effect on plasma α- and γ-tocopherol concentrations. Furthermore, they show that the consumption of supplements is a major contributor to overall intake and has a significant effect on plasma vitamin E concentrations in the Irish population.
authors.affiliation: UCD Institute of Food and Health, University College Dublin,Dublin 4,Republic of Ireland.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: UCD Institute of Food and Health, University College Dublin,Dublin 4,Republic of Ireland.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Monahan
authors.affiliation: UCD Institute of Food and Health, University College Dublin,Dublin 4,Republic of Ireland.
authors.forename: Breige A
authors.initials: BA
authors.lastname: McNulty
authors.affiliation: UCD Institute of Food and Health, University College Dublin,Dublin 4,Republic of Ireland.
authors.forename: Mike J
authors.initials: MJ
authors.lastname: Gibney
authors.affiliation: UCD Institute of Food and Health, University College Dublin,Dublin 4,Republic of Ireland.
authors.forename: Eileen R
authors.initials: ER
authors.lastname: Gibney
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002079:Butter; D004032:Diet; D004042:Dietary Fats, Unsaturated; D019587:Dietary Supplements; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage; D006801:Humans; D007494:Ireland; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D064167:Recommended Dietary Allowances; D014675:Vegetables; D014810:Vitamin E / Q000008:administration & dosage*; D014815:Vitamins / Q000008:administration & dosage; D055815:Young Adult; D024502:alpha-Tocopherol / Q000097:blood*; D024504:gamma-Tocopherol / Q000097:blood*
chemical_list: D004042:Dietary Fats, Unsaturated; D005395:Fish Oils; D014815:Vitamins; D014810:Vitamin E; D002079:Butter; D024504:gamma-Tocopherol; D024502:alpha-Tocopherol