title: Contribution of cod liver oil-related nutrients (vitamins A, D, E and eicosapentaenoic acid and docosahexaenoic acid) to daily nutrient intake and their associations with plasma concentrations in the EPIC-Norfolk cohort.
abstract: BACKGROUND
  Total nutrient intake (TNI) is intake from food and supplements. This provides an assessment of nutrient adequacy and the prevalence of excessive intake, as well as the response with respect to biomarkers. Cod liver oil (CLO) is the most frequently consumed supplement in the UK, containing nutrients that might have varying influences on health. We calculated TNI for vitamins A, D and E, as well as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and assessed associations with the respective blood concentrations.
  
  
  METHODS
  Seven-day diet diaries and blood samples were taken from two subsets of the European Prospective Investigation into Cancer (EPIC-Norfolk) cohort (age range 39-79 years; n = 1400 for vitamin D; n = 6656 for remaining nutrients). TNI was calculated for the subgroups: nonsupplement users, those consuming the nutrient in supplement form and those consuming a supplement without this nutrient.
  
  
  RESULTS
  CLO-related nutrients were supplemented by 15%-33%, which approximately doubled median intakes. Almost everyone in the supplement + vitamin A group reached the estimated average requirement; however, guideline levels were likely to be exceeded. Partial correlations between intake of vitamins A and D and biomarkers were low and modestly strengthened by the inclusion of supplement sources (correlation = 0.01-0.13). Correlations between biomarker and TNI of vitamin E and EPA+DHA were in the range 0.40-0.46; however, vitamin E exceeding food intake resulted in attenuated coefficients. Linear associations between food or TNI EPA+DHA and plasma were weak but consistent across subgroups.
  
  
  CONCLUSIONS
  CLO-related nutrients contribute substantially to nutrient intake, with a risk of over-consumption. Apart from EPA+DHA, biomarker data suggest that CLO-related nutrients in supplements are not linearly associated with vitamin status.
authors.affiliation: Department of Public Health & Primary Care, EPIC-Norfolk Study, University of Cambridge, Cambridge, UK.
authors.forename: M A H
authors.initials: MA
authors.lastname: Lentjes
authors.affiliation: Department of Public Health & Primary Care, EPIC-Norfolk Study, University of Cambridge, Cambridge, UK.
authors.forename: A A
authors.initials: AA
authors.lastname: Mulligan
authors.affiliation: Norwich Medical School, Department of Population Health and Primary Care, University of East Anglia, Norwich, UK.
authors.forename: A A
authors.initials: AA
authors.lastname: Welch
authors.affiliation: Department of Public Health & Primary Care, EPIC-Norfolk Study, University of Cambridge, Cambridge, UK.
authors.forename: A
authors.initials: A
authors.lastname: Bhaniani
authors.affiliation: Department of Public Health & Primary Care, EPIC-Norfolk Study, University of Cambridge, Cambridge, UK.
authors.forename: R N
authors.initials: RN
authors.lastname: Luben
authors.affiliation: University of Cambridge, School of Clinical Medicine, Clinical Gerontology Unit, Cambridge, UK.
authors.forename: K-T
authors.initials: KT
authors.lastname: Khaw
mesh_terms: D000328:Adult; D000368:Aged; D003060:Cod Liver Oil / Q000097:blood*; D015331:Cohort Studies; D004032:Diet / Q000706:statistics & numerical data; D019587:Dietary Supplements / Q000706:statistics & numerical data; D004281:Docosahexaenoic Acids / Q000097:blood*; D004435:Eating; D015118:Eicosapentaenoic Acid / Q000097:blood*; D005060:Europe; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys / Q000706:statistics & numerical data; D011446:Prospective Studies; D006113:United Kingdom; D014801:Vitamin A / Q000097:blood*; D014807:Vitamin D / Q000097:blood*; D014810:Vitamin E / Q000097:blood*; D014815:Vitamins / Q000097:blood
chemical_list: D014815:Vitamins; D014801:Vitamin A; D014807:Vitamin D; D014810:Vitamin E; D004281:Docosahexaenoic Acids; D003060:Cod Liver Oil; D015118:Eicosapentaenoic Acid
keywords: biomarkers; cohort study; dietary assessment; dietary supplements; total nutrient exposure