Five decades after its adoption, albumin-adjusted calcium remains widely used, despite substantial limitations. In this editorial introducing a special issue of Pathology, Chiang and Choy highlight a companion review arguing that adjusted calcium is unreliable in elderly, critically ill, and renally impaired patients, where pH and protein disturbances can undermine the assumptions behind correction formulas. The editorial warns that universal provision of albumin-adjusted calcium can lead to misdiagnosis of true hypo- or hypercalcaemia, and notes that the concept of “corrected calcium” has been challenged since the 1970s. The authors say the accumulating evidence supports replacing this practice with ionised calcium.

The concept of “corrected calcium” was challenged as early as 1975. The evidence has been building for decades, yet albumin-adjusted calcium remains widely used.

The takeaway: The authors caution against the continued universal reporting of albumin-adjusted calcium and point to ionised calcium as the preferred alternative. At minimum, clinicians should be aware of its limitations.

The authors stated that there are no conflicts of interest to disclose.

Source: Pathology