Unintentional self-intoxication with inorganic calcium

A 40-year-old woman with previous parathyroidectomy for adenoma was found to have a serum calcium level of 5.35 mmol l-1 (21.4 mg dl-1). Inadvertent calcium overdose had occurred because of her mistaken belief that if some prescribed calcium was good, then more was better. Her misconception is in contrast with that of patients with Münchausen's syndrome, who deliberately made themselves hypercalcaemic by ingesting calcium or Vitamin D surreptitiously. Inorganic calcium is increasingly promoted for its presumed, though unproven, effectiveness in prevention and treatment of osteoporosis. Massive overdose can be associated with serious risks, as illustrated by the present case, which we believe represents the highest serum calcium level yet reported in an ambulatory patient.