Alicia K Heath1, Elizabeth J Williamson, Peter R Ebeling, David Kvaskoff, Darryl W Eyles, Dallas R English. 1. Centre for Epidemiology and Biostatistics (A.K.H., E.J.W., D.R.E.), Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria 3010, Australia; Cancer Epidemiology Centre (A.K.H., E.J.W., D.R.E.), Cancer Council Victoria, Melbourne, Victoria 3004, Australia; Department of Epidemiology and Preventive Medicine (E.J.W.), Monash University, Melbourne, Victoria 3004, Australia; NorthWest Academic Centre (P.R.E.), The University of Melbourne and Western Health, St Albans, Victoria 3021, Australia; Queensland Brain Institute (D.K., D.W.E.), The University of Queensland, St Lucia, Queensland 4072, Australia; and Queensland Centre for Mental Health Research (D.W.E.), The Park Centre for Mental Health, Wacol, Queensland 4076, Australia.
Abstract
CONTEXT: Recognition that vitamin D might be associated with many chronic diseases has led to large-scale epidemiological and clinical studies. Dried blood spots (DBS) are a useful resource for these studies. Consequently, accurate, efficient, and inexpensive assays to quantify 25-hydroxyvitamin D (25OHD) in DBS are required. OBJECTIVE: This study evaluated the validity and reliability of a liquid chromatography-tandem mass spectrometry assay for measuring 25OHD in archived DBS and compared measurements of 25OHD in DBS with those in plasma. DESIGN AND PARTICIPANTS: Sixty-two participants in the Melbourne Collaborative Cohort Study who had plasma and matching DBS stored since study entry in the early 1990s were randomly selected for a study calibrating 25OHD concentrations in DBS with plasma. As part of a study of vitamin D and mortality, cancer, and diabetes, we also assessed the reliability of measurements from DBS using 500 replicates placed randomly within 31 batches run over 15 months. OUTCOME MEASURE: 25OHD concentrations were measured by liquid chromatography-tandem mass spectrometry. RESULTS: There was good agreement between measurements of 25OHD from DBS and plasma; R(2) = 0.73 from a regression of plasma concentration on DBS concentration. The within-batch and between-batch intraclass correlations from the 500 replicate measurements were 0.82 (95% confidence interval, 0.80, 0.85) and 0.73 (95% confidence interval, 0.68, 0.78), respectively. CONCLUSIONS: Measuring 25OHD in DBS is a valid and reliable alternative to measuring 25OHD in sera or plasma. A simple calibration model was developed to convert measurements from DBS to equivalent plasma measurements, thus enabling comparisons against clinical reference ranges and with studies using sera or plasma samples.
CONTEXT: Recognition that vitamin D might be associated with many chronic diseases has led to large-scale epidemiological and clinical studies. Dried blood spots (DBS) are a useful resource for these studies. Consequently, accurate, efficient, and inexpensive assays to quantify 25-hydroxyvitamin D (25OHD) in DBS are required. OBJECTIVE: This study evaluated the validity and reliability of a liquid chromatography-tandem mass spectrometry assay for measuring 25OHD in archived DBS and compared measurements of 25OHD in DBS with those in plasma. DESIGN AND PARTICIPANTS: Sixty-two participants in the Melbourne Collaborative Cohort Study who had plasma and matching DBS stored since study entry in the early 1990s were randomly selected for a study calibrating 25OHD concentrations in DBS with plasma. As part of a study of vitamin D and mortality, cancer, and diabetes, we also assessed the reliability of measurements from DBS using 500 replicates placed randomly within 31 batches run over 15 months. OUTCOME MEASURE: 25OHD concentrations were measured by liquid chromatography-tandem mass spectrometry. RESULTS: There was good agreement between measurements of 25OHD from DBS and plasma; R(2) = 0.73 from a regression of plasma concentration on DBS concentration. The within-batch and between-batch intraclass correlations from the 500 replicate measurements were 0.82 (95% confidence interval, 0.80, 0.85) and 0.73 (95% confidence interval, 0.68, 0.78), respectively. CONCLUSIONS: Measuring 25OHD in DBS is a valid and reliable alternative to measuring 25OHD in sera or plasma. A simple calibration model was developed to convert measurements from DBS to equivalent plasma measurements, thus enabling comparisons against clinical reference ranges and with studies using sera or plasma samples.
Authors: Steffen U Thorsen; Karl Mårild; Sjurdur F Olsen; Klaus K Holst; German Tapia; Charlotta Granström; Thorhallur I Halldorsson; Arieh S Cohen; Margaretha Haugen; Marika Lundqvist; Torild Skrivarhaug; Pål R Njølstad; Geir Joner; Per Magnus; Ketil Størdal; Jannet Svensson; Lars C Stene Journal: Am J Epidemiol Date: 2018-06-01 Impact factor: 4.897
Authors: Gayle C Windham; Michelle Pearl; Meredith C Anderson; Victor Poon; Darryl Eyles; Karen L Jones; Kristen Lyall; Martin Kharrazi; Lisa A Croen Journal: Autism Res Date: 2019-03-18 Impact factor: 5.216
Authors: Ramune Jacobsen; Steffen U Thorsen; Arieh S Cohen; Marika Lundqvist; Peder Frederiksen; Christian B Pipper; Flemming Pociot; Lau C Thygesen; Alberto Ascherio; Jannet Svensson; Berit L Heitmann Journal: Diabetologia Date: 2016-05-30 Impact factor: 10.122
Authors: Anne Marie Z Jukic; Allen J Wilcox; D Robert McConnaughey; Clarice R Weinberg; Anne Z Steiner Journal: Epidemiology Date: 2018-05 Impact factor: 4.822
Authors: Barbara Altieri; Etienne Cavalier; Harjit Pal Bhattoa; Faustino R Pérez-López; María T López-Baena; Gonzalo R Pérez-Roncero; Peter Chedraui; Cedric Annweiler; Silvia Della Casa; Sieglinde Zelzer; Markus Herrmann; Antongiulio Faggiano; Annamaria Colao; Michael F Holick Journal: Eur J Clin Nutr Date: 2020-01-06 Impact factor: 4.016