Background <p>Symptomatic hypocalcemia is an uncommon metabolic disturbance in palliative care and may therefore be overlooked. While deprescribing is a key principle in this setting, routine discontinuation of calcium and vitamin D supplementation may be harmful in selected high-risk patients, particularly after recent antiresorptive therapy.</p> Case presentation <p>A 74-year-old woman with hormone receptor-positive metastatic breast cancer, extensive bone metastases and chronic kidney disease, was admitted to a German palliative care unit. Four weeks prior, she had received zoledronic acid, and calcium and vitamin D supplementation were discontinued on admission. She subsequently developed persistent nausea, vomiting and bronchospasm without classical neuromuscular signs, which were initially attributed to other causes. At a corrected calcium nadir of 0.95 mmol/L intravenous calcium was started and symptoms resolved. Oral intake resumed and supplementation was restarted. She was discharged to hospice care and died nine months later.</p> Conclusion <p>After recent antiresorptive therapy, especially in patients with additional risk factors such as renal impairment, hypocalcemia may present with atypical symptoms including nausea or bronchospasm. This case highlights a potential pitfall of deprescribing in palliative care and underscores the need for individualized decisions regarding calcium and vitamin D supplementation to prevent delayed diagnosis and avoidable symptom burden.</p>