Assessment of vitamin D status and definition of a normal circulating range of 25-hydroxyvitamin DHollis, Bruce WCurrent Opinion in Endocrinology, Diabetes and Obesity: December 2008 - Volume 15 - Issue 6 - p 489–494 doi: 10.1097/MED.0b013e328317ca6c Parathyroids, bone and mineral metabolism: Edited by Daniel Baran Buy Abstract Author InformationAuthors Article MetricsMetrics Purpose of review The assessment of circulating 25-hydroxyvitamin D [25(OH)D] for clinical diagnosis has increased in an exponential fashion during the past 5 years. It is thus timely to review the reasons for this increase as well as the diverse analytical methods used to meet this need. Recent findings Nutritional vitamin D status, as defined by circulating levels of 25(OH)D, has long been implicated in skeletal health. However, in the past decade circulating 25(OH)D has been strongly linked in humans to cancer rates, autoimmune disease, cardiovascular health and infectious disease. As a result, availability and rapid analytical turnaround of 25(OH)D assays have had to improve. Today these demands are largely met in the clinical laboratory by direct automated chemiluminescent platform analysis or high-throughput LC/MS procedures. These methods are diverse and often do not agree with respect to designated reference ranges. Summary The assessment of circulating 25(OH)D levels has become an important clinical tool in the management and prevention of diverse disease states. For this reason, assay standardization as well as a uniform reference range for circulating 25(OH)D levels must be achieved. Medical University of South Carolina, Charleston, South Carolina, USA Correspondence to Bruce W. Hollis, PhD., Medical University of South Carolina, Department of Pediatrics, Darby Children's Research Institute, 173 Ashley Ave., Room 313, Charleston, SC 29425, USA Tel: +1 843 792 6854; fax: +1 843 792 1844; e-mail: email@example.com Disclosure: Dr Hollis is an academic consultant to the DiaSorin Corp. © 2008 Lippincott Williams & Wilkins, Inc.