The DEQAS Advisory Panel

Glenville Jones



Current Position: Craine Professor of Biochemistry, Department of Biomedical & Molecular Sciences & Professor, Department of Medicine, Queen’s University, Kingston, ON Canada.

Glen has worked in the vitamin D field for 45 years. Trained in the UK (Liverpool), Canada (Calgary) and USA (Wisconsin); he was a professor at the University of Toronto & Research Scientist at the Hospital for Sick Children before moving to Queen’s University in 1984, where he has served as Head of Biochemistry (2002-2011). Glen discovered several metabolites of vitamin D2 and was involved in the early design and application of clinical assays for vitamin D metabolites in patients with disorders of calcium homeostasis. Other interests include the studies of the cytochrome P450-based enzymes of vitamin D & A metabolism; and the mass spectrometry (LC-MS/MS) of small molecules. In 2006, he was recognized for his career contributions to vitamin D research by the Vitamin D Workshops. In 2014, Glen was awarded the Queen’s University Prize for Excellence in Research. He was a member of IOM Committee that set the 2011 nutritional recommendations (DRIs) for vitamin D & calcium for North Americans. Glen was co-founder of the Queen’s biotechnology company, Cytochroma Inc., now part of OPKO-Renal (Miami, FL), for which he now serves on the Research Advisory Board.

Graham Carter


DEQAS Organiser

Graham started his professional career as a medical laboratory technician in a District General Hospital. After obtaining an MSc in clinical biochemistry at the University of Surrey (1972) he moved to London's Charing Cross Hospital as a Senior Biochemist. He was appointed Consultant Clinical Scientist in 1991 and remained in this post until his retirement from full time employment in September 2000. He was appointed an Honorary Senior Research Fellow of Imperial College, London in 2001.

Graham's interest in vitamin D was stimulated by a visit to Dr. Richard Gray's laboratory at The Medical College of Wisconsin in the mid -1970's. The vitamin D EQAS was started in 1989 after two regional surveys revealed serious shortcomings in the performance of 25 hydroxyvitamin D assays. He was a member of the Advisory Panel for the Randox International Quality Assessment Scheme (RIQAS) from 1996 - 2002.

Jacqueline Berry


Jackie is a Senior Research Fellow in the Vitamin D Research Laboratories at the University of Manchester. She started her career as a Pharmacologist gaining a BSc from Leeds University (1972), followed by an MSc (1974) and PhD (1977) from the University of Manchester. Following a short period in the Department of Surgery she moved to the Department of Medicine to work with Professor Barbara Mawer in 1979. This started a lifelong interest in metabolic bone disease with a particular focus on vitamin D and assay methodology. In the early 1980s she helped develop an improved assay for measurement of 1,25-dihydroxyvitamin D (1,25D) using a monoclonal antibody, and this in-house assay is still in use today. Since 1994 she has been Deputy Director of the only Supraregional Assay Service in England and Wales for the combined assay of 25-hydroxyvitamin D with 1,25D, for which she gained ISO 9001:2000 and ISO 13485:2003 accreditation. Current research sponsored by Cancer Research UK and Food Standards Agency examines the relative contributions of diet and UV exposure to vitamin D "sufficiency" in the British population. She is a committee member of the British Bone Research Society.

Elaine Gunter


Elaine Gunter B.S., MT(ASCP) was chief of the NHANES Laboratory (Centers for Disease Control and Prevention) from 1978-2001. This world-class nutritional biochemistry laboratory specializes in assays for vitamins, trace elements, and nutritional anemias, and was founded in 1971 as the central laboratory for the National Health and Nutrition Examination Survey of the United States. Data from NHANES provided the first national normative estimates of vitamin D status in the U.S. population. Elaine's laboratory also provided the vitamin D analyses for the NCI-funded Navy Colon Adenoma Study, which demonstrated the efficacy of vitamin D supplementation in prevention of colon cancer, and for a number of other related vitamin D studies.

Elaine co-founded and served as the first president of ISBER, the International Society for Biological and Environmental Repositories. From 2001-2005, she was Deputy Director for Management and Operations of the Division of Laboratory Sciences (the chemistry side of CDC), responsible for ensuring the successful management of all the personnel, facilities, procurement, contractual grants, and operational processes for a staff of 300 scientists. She is now an independent consultant in biorepositories and laboratory activities, and continues to make scientific contributions in those fields.


Karen is a group leader in the Biomolecular Measurement Division of the National Institute of Standards and Technology (NIST). She received her Ph.D. in analytical chemistry from the University of Hawaii - Manoa and joined NIST in 1994 as a postdoctoral research associate. Her expertise is in chromatographic separations and mass spectrometry and their application to quantitative measurements. Her work has included the development of analytical methods for vitamins and other analytes in dietary supplements, and she has coordinated the development of serum-based Standard Reference Materials (SRMs) for nutritional biomarkers, including vitamin D metabolites.


Chris is the Coordinator for the Vitamin D Standardization Program (VDSP) at the US National Institutes of Health, Office of Dietary Supplements. The goal of the VDSP is to standardize the laboratory measurement of 25-hydroxyvitamin D [25(OH)D] to improve clinical and public health practice worldwide. He received his Ph.D. in nutritional sciences from the University of Wisconsin-Madison in 1982.  The VDSP developed a reference measurement system to support standardization efforts.  Included in that system was support for the development of (1) NIST reference measurement procedures and Standard Reference Materials development; and (2) CDC’s Vitamin D Standardization-Certification Program (VDSCP); as well as (3) manuals with step by step guides for the standardization of routine clinical and research laboratories; (4) a research program to evaluate the accuracy and precision of commercial and laboratory developed 25(OH)D assays; and (5) the conversion of DEQAS to an accuracy-based PT/EQA. 


Ramon is Professor of Public Health Sciences in the Department of Public Health Sciences at Loyola University Medical Center where he serves as the head of the Biostatistics Division and co-director of the Master's Program in Clinical Research Methods. He has a strong background in mathematics and computer intensive statistical methods. He received his Ph.D. from the University of Arizona in Applied Mathematics, where he spent three years teaching mathematics and statistics courses.

Ramon is an active member of the American Statistical Association. In 2000, he served as the program chair for the section in Epidemiology. He has organized sessions on Minority and Health and Diversity and the Risk of Cardiovascular Disease for the Association annual meetings and been appointed to the Committee of Minorities in Statistics (2003-2005, 2005-2008). He is also a member of the Eastern North American Region (ENAR) of the International Biometry Society for whom he moderated a workshop to discuss issues related to minority graduate students in Biostatistics. He is a member of the Society for the Advancement of Chicanos and Native Americans in Science (SACNAS). He was a member of the IOM Committee to Review Dietary Reference Intakes for Vitamin D and Calcium in North America.


Patrick Twomey is consultant chemical pathologist in St. Vincent's University Hospital, Dublin, the Laboratory Director for Clinical Chemistry within the St Vincent's Hospital Group and Associate Clinical Professor in the School of Medicine, University College Dublin. He obtained an Intercalated BSc in Biochemistry from University College Cork before being awarded his Medical degree. He is a Fellow of both the Faculty of Pathology at the Royal College of Physicians of Ireland and of the Royal College of Pathologists where he also is an examiner. He is the Acting Chair of the Joint Working Group on Quality Assessment in Pathology and past Chair of the Chemical Pathology National Quality Assurance Advisory Panel within the Royal College of Pathologists. He is Vice Dean of the Faculty of Pathology, Royal College of Physicians of Ireland and Treasurer of the Association of Clinical Pathologists. He has co-authored one text book, several book chapters and over 80 original publications in the fields of clinical biochemistry, metabolic medicine, lipids and nutrition. He is a member of the editorial boards of the Journal of Clinical Pathology and of the British Medical Journal Case Reports.


Current Position: Professor of Clinical Chemistry, University of Liège & Head of the Department of Clinical Chemistry, CHU de Liège, Belgium.

Etienne was trained as a PharmD at the University of Liege and then underwent a 5-years advanced master in Laboratory medicine. He passed his PhD thesis, on parathormone, in 2010. Since 2012, he is Professor of Clinical Chemistry at the University of Liege and Head of the Department of Clinical Chemistry at the University hospital of Liège, Belgium. Etienne’s main scientific fields of interest are linked with the phosphocalcic metabolism, especially in patients suffering from chronic kidney diseases, but he has also been working in other domains like frailty, sarcopenia, estimation of renal function and vascular calcifications. He is member of the scientific board of different societies, like IOF, ESCEO, GRIO and ERA-EDTA: CKD-MBD working group. He is also chairing the IFCC working group on the standardization of bone biomarkers.