An international coalition of experts in laboratory medicine, osteoporosis, and chronic kidney disease is calling for laboratories to stop routinely reporting albumin-adjusted (“corrected”) calcium, arguing that the longstanding practice is outdated, unreliable in many clinical settings, and may contribute to patient harm.

The recommendation appears in the new position statement Albumin-adjusted (‘corrected’) calcium should no longer be reported, published in the journal Clinical Chemistry and Laboratory Medicine, by a working group representing the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Committee: Chronic Kidney Diseases, and the Joint International Osteoporosis Foundation (IOF) Working Group and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Committee on Bone Metabolism.

For decades, laboratories have used mathematical formulas to “correct” total calcium levels according to albumin concentration, based on the assumption that this would provide a more accurate estimate of biologically active calcium. However, the authors argue that mounting evidence now shows these correction formulas often perform poorly — especially in patients with chronic illness, kidney disease, inflammation, acid-base disturbances, or low albumin levels.

“Albumin-adjusted calcium has become deeply embedded in clinical practice despite limited validation against ionised calcium, which is the biologically active form,” said lead author Professor Etienne Cavalier, University of Liège and Chair of the Joint IOF Working Group and IFCC Committee on Bone Metabolism. “Current evidence indicates that these corrections can actually worsen diagnostic accuracy and mask clinically important abnormalities.”

The statement highlights recent large-scale studies showing that unadjusted total calcium frequently agrees better with ionized calcium than commonly used correction formulas. In some cases, corrected calcium may falsely normalize true hypocalcemia or incorrectly suggest hypercalcemia.

The concerns are particularly important in patients with advanced chronic kidney disease or those receiving dialysis, where calcium balance directly influences treatment decisions involving vitamin D analogues, calcimimetics, phosphate binders, and dialysis prescriptions.

The authors also note that albumin correction introduces additional analytical uncertainty and lacks standardization across laboratories because results vary depending on local albumin measurement methods and patient populations.

Instead of routine correction, the expert groups recommend:

• Reporting total calcium as the default laboratory result
• Ordering ionized calcium when calcium status is clinically important or difficult to interpret
• Using ionized calcium as the preferred first-line test in patients with severe hypoalbuminemia or those on dialysis, provided appropriate quality and sampling standards are followed

The paper also identifies substantial international variability in current laboratory practice, with some laboratories never reporting corrected calcium, while others generate it automatically whenever calcium and albumin are measured together.

The authors conclude that abandoning routine albumin-adjusted calcium reporting would improve consistency, reduce diagnostic confusion, and better align laboratory medicine with contemporary evidence and physiology.

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Reference 
Cavalier, Etienne, Zima, Tomáš, Plebani, Mario, Langlois, Michel, Harvey, Nicholas C., McCloskey, Eugene V., Rizzoli, René, Makris, Konstantinos, Vasikaran, Samuel and On behalf of the European Federation of Clinical Chemistry and Laboratory Medicine Committee: Chronic Kidney Diseases and the Joint International Osteoporosis Foundation Working Group and International Federation of Clinical Chemistry and Laboratory Medicine Committee on Bone metabolism,. "Albumin-adjusted (“corrected”) calcium should no longer be reported: a position statement from the Joint IOF Working Group and IFCC Committee on Bone Metabolism and EFLM Committee on CKD" Clinical Chemistry and Laboratory Medicine (CCLM). https://doi.org/10.1515/cclm-2026-0545

About IOF
The International Osteoporosis Foundation (IOF) is the world’s largest nongovernmental organization dedicated to the prevention, diagnosis, and treatment of osteoporosis and related musculoskeletal diseases. Its members — including committees of leading scientific researchers and 349 patient, medical, and research organizations across 152 countries — work together to make fracture prevention and healthy mobility a global healthcare priority. https://www.osteoporosis.foundation   @iofbonehealth

About IFCC
The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) is a worldwide, non-political organization for clinical chemistry and laboratory medicine. As such it has a range of roles that include (1) global standard setting in collaboration with other international organizations, (2) supporting its members through scientific and educational endeavour, and (3) providing a series of congresses, conferences and focussed meetings in order for laboratory medicine specialists to meet and present original findings and best practice. https://www.ifcc.org/

About EFLM
The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) is a federation of national societies representing clinical chemistry and laboratory medicine across Europe. It promotes excellence in laboratory medicine through science, education, and harmonisation of professional standards, with the aim of improving patient care and supporting the development of the profession throughout Europe. https://www.eflm.eu/site/