title: Dietary sources of vitamin B-12 and their association with plasma vitamin B-12 concentrations in the general population: the Hordaland Homocysteine Study.
abstract: BACKGROUND
  Limited information is available on the association between vitamin B-12 status and intake from different dietary sources.
  
  
  OBJECTIVE
  We investigated the relation of dietary intake of different food items with plasma vitamin B-12 concentrations in the general population.
  
  
  METHODS
  A cross-sectional, population-based study of 5937 subjects in 2 age groups (47-49 and 71-74 y) from the Hordaland Homocysteine Study in Norway was conducted by using a food-frequency questionnaire and measurements of plasma vitamin B-12 concentrations.
  
  
  RESULTS
  A significant difference in plasma vitamin B-12 concentrations was observed with increasing total vitamin B-12 intake. A plateau was reached at an intake of approximately 10 microg/d. Plasma vitamin B-12 was associated with intakes of increasing amounts of vitamin B-12 from dairy products or fish (P for trend <0.001 for both) but not with intakes of vitamin B-12 from meat or eggs. For the same content of vitamin B-12, intake from dairy products led to the greatest increase in plasma vitamin B-12. Total intake of vitamin B-12, particularly from milk and fish, decreased the risk of vitamin B-12 concentrations <200 pmol/L and impaired vitamin B-12 function (vitamin B-12 <200 pmol/L and methylmalonic acid >0.27 micromol/L) in the total group and in 71-74-y-old subjects.
  
  
  CONCLUSIONS
  Dietary intake of dairy products and fish are significant contributors to plasma vitamin B-12 and may improve plasma vitamin B-12 status. Vitamin B-12 appears to be more bioavailable from dairy products; guidelines for improving vitamin B-12 status should take this into consideration.
authors.affiliation: OPTIMA, Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, UK. anna.vogiatzoglou@dpag.ox.ac.uk
authors.forename: Anna
authors.initials: A
authors.lastname: Vogiatzoglou
authors.forename: A David
authors.initials: AD
authors.lastname: Smith
authors.forename: Eha
authors.initials: E
authors.lastname: Nurk
authors.forename: Paula
authors.initials: P
authors.lastname: Berstad
authors.forename: Christian A
authors.initials: CA
authors.lastname: Drevon
authors.forename: Per M
authors.initials: PM
authors.lastname: Ueland
authors.forename: Stein E
authors.initials: SE
authors.lastname: Vollset
authors.forename: Grethe S
authors.initials: GS
authors.lastname: Tell
authors.forename: Helga
authors.initials: H
authors.lastname: Refsum
mesh_terms: D000368:Aged; D000375:Aging / Q000097:blood / Q000502:physiology; D001682:Biological Availability; D003430:Cross-Sectional Studies; D003611:Dairy Products; D004032:Diet; D004034:Diet Surveys; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D009751:Nutritional Requirements; D009752:Nutritional Status; D017747:Seafood; D011795:Surveys and Questionnaires; D014805:Vitamin B 12 / Q000008:administration & dosage* / Q000097:blood* / Q000493:pharmacokinetics; D014806:Vitamin B 12 Deficiency / Q000453:epidemiology / Q000517:prevention & control; D014803:Vitamin B Complex / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics
chemical_list: D006710:Homocysteine; D014803:Vitamin B Complex; D014805:Vitamin B 12