title: Calcium: total or ionized?
abstract: Measurement of serum total calcium (tCa) has been relied on for assessment of calcium status, despite the fact that it is the ionized calcium (iCa) fraction that has biologic activity. Serum tCa does not accurately predict iCa status in many clinical conditions. For accurate assessment of iCa status, iCa should be directly measured. Anaerobic measurement of serum iCa under controlled conditions provides the most reliable assessment of calcium status; aerobic measurement of iCa with species-specific pH correction is highly correlated with anaerobic measurements.
authors.affiliation: Endocrine Diagnostic Section, Diagnostic Center for Population and Animal Health, Department of Pathobiology and Diagnostic Investigation, Michigan State University, 4125 Beaumont Road, Lansing, MI 48910, USA. schenck5@msu.edu
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Schenck
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Chew
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000502:physiology*; D002118:Calcium / Q000032:analysis* / Q000097:blood / Q000378:metabolism*; D002415:Cats; D004285:Dogs; D006863:Hydrogen-Ion Concentration; D006934:Hypercalcemia / Q000175:diagnosis / Q000209:etiology / Q000662:veterinary*; D006996:Hypocalcemia / Q000175:diagnosis / Q000209:etiology / Q000662:veterinary*; D009752:Nutritional Status; D012016:Reference Values; D013045:Species Specificity
chemical_list: D001798:Blood Proteins; D002118:Calcium