title: Plasma vitamin C and food choice in the third Glasgow MONICA population survey.
abstract: OBJECTIVE
  To determine the contribution of different foods to the estimated intakes of vitamin C among those differing in plasma vitamin C levels, and thereby inform dietary strategies for correcting possible deficiency.
  
  
  METHODS
  Cross sectional random population survey.
  
  
  METHODS
  North Glasgow, Scotland, 1992.
  
  
  METHODS
  632 men and 635 women, aged 25 to 74 years, not taking vitamin supplements, who participated in the third MONICA study (population survey monitoring trends and determinants of cardiovascular disease).
  
  
  RESULTS
  Dietary and sociodemographic information was collected using a food frequency and lifestyle questionnaire. Plasma vitamin C was measured in non-fasted venous blood samples and subjects categorised by cut points of 11.4 and 22.7 micromol/l as being of low, marginal or optimal vitamin C status. Food sources of dietary vitamin C were identified for subjects in these categories. Plasma vitamin C concentrations were compared among groups classified according to intake of key foods. More men (26%) than women (14%) were in the low category for vitamin C status; as were a higher percentage of smokers and of those in the older age groups. Intake of vitamin C from potatoes and chips (fried potatoes) was uniform across categories; while the determinants of optimal versus low status were the intakes of citrus fruit, non-citrus fruit and fruit juice. Optimal status was achieved by a combined frequency of fruit, vegetables and/or fruit juice of three times a day or more except in older male smokers where a frequency greater than this was required even to reach a marginal plasma vitamin C level.
  
  
  CONCLUSIONS
  Fruit, vegetables and/or fruit juice three or more times a day increases plasma vitamin C concentrations above the threshold for risk of deficiency.
authors.affiliation: Centre for Applied Nutrition Research, Matthew Building, University of Dundee, DD1 4HT.
authors.forename: W L
authors.initials: WL
authors.lastname: Wrieden
authors.forename: M K
authors.initials: MK
authors.lastname: Hannah
authors.forename: C
authors.initials: C
authors.lastname: Bolton-Smith
authors.forename: R
authors.initials: R
authors.lastname: Tavendale
authors.forename: C
authors.initials: C
authors.lastname: Morrison
authors.forename: H
authors.initials: H
authors.lastname: Tunstall-Pedoe
mesh_terms: D000328:Adult; D000368:Aged; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000097:blood*; D001206:Ascorbic Acid Deficiency / Q000178:diet therapy / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D004032:Diet / Q000592:standards*; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D012606:Scotland / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology; D012923:Social Class
chemical_list: D015415:Biomarkers; D001205:Ascorbic Acid