Endocrine Abstracts

A 71-year-old man presented to the emergency department with dyspnoea and general weakness. He had a history of stable COPD, coronary artery disease, abdominal aneurysm surgery, and prostate cancer. One month ago, he had survived a SARS-CoV-2 infection. His somatic status was normal, blood pressure was 115/65 mmHg, heart rate was 63/min, he was afebrile 36.6 °C with the exception of SpO2 which was 83%. His initial laboratory results showed severe hypercalcaemia (Ca 3.52 mmol/l), other electrolytes were normal. Due to partial respiratory failure and severe hypercalcaemia, he was admitted to the Department of Internal Medicine. Further laboratory results showed a low PTH level (0.5 pmol/l, reference range 1.3 - 9.3 pmol/l) and a high vitamin D level (> 375 nmol/l). The patient and his family denied misuse of vitamin D supplements. Paraneoplastic hypercalcaemia was suspected, but imaging (US of the neck, CT of the thorax, abdomen and pelvis X-rays revealed no possible substrate). Tumour markers were normal and electrophoresis and immunoelectrophoresis of serum proteins were not suggestive of multiple myeloma. There was also no lymphadenopathy suggestive of lymphoma. At this point in the investigation, we suspected a granulomatous disease and additional sensitive immunological tests were carried out. Hypercalcemia was treated with crystalloid solutions and intravenous zoledronic acid, which led to an improvement in the hypercalcaemia (Ca 3.43 mmol/l – 3.18 mmol/l). At the next outpatient follow-up after discharge from hospital, the serum calcium level decreased accordingly (Ca 2.72- 2.66 mmol/l, iCa++ 1.31- 1.22 mmol/l). The patient admitted that he had been taking vitamin D supplements since overcoming SARS-CoV-2, two capsules of 20000 IJ twice a day.

Conclusion: The hypercalcaemia in this patient is a consequence of continued vitamin D therapy after treatment of the SARS-CoV-2 infection. More frequent monitoring and patient education on the use of supplements is required.