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However, use of alternative measurements of calcium and vitamin D showed that these results were spurious. Clinicians looking after patients with significant paraprotein concentrations or other significant protein abnormalities should be aware of the possibility of assay interference when reviewing their biochemistry results. This awareness can be vital in avoiding unnecessary investigations or treatments, thus not only saving resources but also protecting patients from harm that may be caused by inappropriate therapies.<\/jats:p>","DOI":"10.1093\/ejendo\/lvaf151","type":"journal-article","created":{"date-parts":[[2025,7,25]],"date-time":"2025-07-25T11:43:37Z","timestamp":1753443817000},"page":"K1-K4","source":"Crossref","is-referenced-by-count":2,"title":["Paraprotein-induced spurious hypercalcaemia: diagnostic pitfalls in two cases"],"prefix":"10.1093","volume":"193","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-3501-7218","authenticated-orcid":false,"given":"Nathan","family":"Lorde","sequence":"first","affiliation":[{"name":"Department of Endocrinology, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust , Mindelsohn Way, Birmingham B15 2GW, UK"},{"name":"Department of Clinical Chemistry, Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust , 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