title: Vitamin D status from dried capillary blood samples.
abstract: BACKGROUND
  Given the huge impact of vitamin D deficiency on a broad spectrum of diseases such as rickets, osteoporosis, mineral bone disease-vascular calcification syndrome, infectious diseases, but also several types of cancer and CNS diseases, reliable and simple methods to analyze the vitamin D status are urgently needed.
  
  
  METHODS
  We developed an easy technique to determine the 25-OH vitamin D status from dried blood samples on filter paper. This allows determination of the 25-OH vitamin D status independently of venous blood taking, since only sampling of capillary blood is required for this new method. We compared the results of vitamin D measurements from venous blood of 96 healthy blood donors with those from capillary blood taken from the same patients at the same time. The capillary blood was dried on filter paper using the D-Vital ID dry-blood collection system.
  
  
  RESULTS
  25-OH vitamin D concentration data from extracted dried capillary blood filters correlated very well with data obtained after direct measurement of venous blood samples of the same blood donor (R: 0.7936; p < 0.0001). The correlation was linear over the whole range of 25-OH vitamin D concentrations seen in this study. A Bland-Altman plot revealed good agreement between both tests.
  
  
  CONCLUSIONS
  The D-Vital ID dry-blood collection system showed an excellent performance as compared to the classical way of 25-OH vitamin D measurement from venous blood. This new technique will facilitate easy and reliable measurement for vitamin D status, in particular, in rural or isolated areas, developing countries, and field studies.
authors.affiliation: Institute of Nutritional Science, University of Potsdam, Potsdam-Rehbrücke, Germany. hocher@uni-potsdam.de
authors.forename: Berthold
authors.initials: B
authors.lastname: Hocher
authors.forename: Hans Jürgen
authors.initials: HJ
authors.lastname: Grön
authors.forename: Claudia
authors.initials: C
authors.lastname: Schumann
authors.forename: Oleg
authors.initials: O
authors.lastname: Tsuprykov
authors.forename: Susanne
authors.initials: S
authors.lastname: Seifert
authors.forename: Walter E
authors.initials: WE
authors.lastname: Hitzler
authors.forename: Franz Paul
authors.initials: FP
authors.lastname: Armbruster
mesh_terms: D002196:Capillaries; D006801:Humans; D012016:Reference Values; D014807:Vitamin D / Q000097:blood*
chemical_list: D014807:Vitamin D