A Curious Case of Hypervitaminosis D-related Hypercalcemia

Abstract

Abstract Hypercalcemia can manifest with various symptoms and poses diagnostic challenges due to its multifactorial etiology. This case highlights a 74-year-old patient with hypercalcemia of complex origin. The patient had a history of chronic liver disease, chronic kidney disease, and a previous episode of hypercalcemia associated with excessive oral Vitamin D intake. On admission, the patient presented with disorientation and increased drowsiness. Further evaluation revealed persistently high serum calcium levels, low parathyroid hormone levels, and elevated levels of Vitamin D. Investigations identified a duodenal nodule with multiple lymph node enlargement, suggesting a malignancy as the underlying cause. Other potential factors contributing to hypercalcemia, such as a granulomatous disease, prolonged immobilization, and a deactivating mutation of the 24-hydroxylase gene (CYP24A1), were also considered. Despite interventions, including hemodialysis and denosumab administration, the patient’s condition deteriorated due to sepsis and hypotensive shock, ultimately resulting in death. This case emphasizes the importance of considering multiple etiologies in cases of hypercalcemia in the elderly and the challenges involved in managing severe symptomatic hypercalcemia. Medical professionals must employ sound clinical reasoning and comprehensive diagnostic approaches to accurately identify and address the underlying cause. Hemodialysis may be necessary in refractory cases to achieve serum calcium normalization.