title: Quantitative data on the magnitude of the systemic inflammatory response and its effect on micronutrient status based on plasma measurements.
abstract: BACKGROUND
  Plasma concentrations of several trace elements and vitamins decrease because of the systemic inflammatory response. Thus, low values do not necessarily indicate deficiency.
  
  
  OBJECTIVE
  The magnitude of this effect on plasma micronutrient concentrations was investigated to provide guidance on the interpretation of routine clinical results.
  
  
  METHODS
  Between 2001 and 2011, the results (2217 blood samples from 1303 patients) of routine micronutrient screens (plasma zinc, copper, selenium, and vitamins A, B-6, C, and E) and all vitamin D results (4327 blood samples from 3677 patients) were extracted from the laboratory database. C-reactive protein concentrations were measured as a marker of the severity of inflammation and categorized into 6 groups; for each group, plasma micronutrient concentrations and percentage changes were calculated.
  
  
  RESULTS
  Except for copper and vitamin E, all plasma micronutrient concentrations decreased with increasing severities of the acute inflammatory response. For selenium and vitamins B-6 and C, this occurred with only slightly increased C-reactive protein concentrations of 5 to 10 mg/L. For each micronutrient, the change in plasma concentrations varied markedly from patient to patient. The magnitude of the effect was greatest for selenium and vitamins A, B-6, C, and D, for which the median plasma concentrations decreased by >40%.
  
  
  CONCLUSIONS
  The clinical interpretation of plasma micronutrients can be made only with knowledge of the degree of inflammatory response. A reliable clinical interpretation can be made only if the C-reactive protein is <20 mg/L (plasma zinc), <10 mg/L (plasma selenium and vitamins A and D), or <5 mg/L (vitamins B-6 and C).
authors.affiliation: Scottish Trace Elements and Micronutrient Reference Laboratory, Department of Clinical Biochemistry, Faculty of Medicine, University of Glasgow, Royal Infirmary, United Kingdom. andrew.duncan@ggc.scot.nhs.uk
authors.forename: Andrew
authors.initials: A
authors.lastname: Duncan
authors.forename: Dinesh
authors.initials: D
authors.lastname: Talwar
authors.forename: Donald C
authors.initials: DC
authors.lastname: McMillan
authors.forename: Fiona
authors.initials: F
authors.lastname: Stefanowicz
authors.forename: Denis St J
authors.initials: DS
authors.lastname: O'Reilly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001361:Avitaminosis / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D003951:Diagnostic Errors; D005260:Female; D017408:Guidelines as Topic; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000150:complications*; D008297:Male; D018977:Micronutrients / Q000097:blood* / Q000172:deficiency; D008875:Middle Aged; D015596:Nutrition Assessment; D009752:Nutritional Status; D012643:Selenium / Q000097:blood; D014815:Vitamins / Q000097:blood*; D055815:Young Adult
chemical_list: D018977:Micronutrients; D014815:Vitamins; D002097:C-Reactive Protein; D012643:Selenium