Hypercalcemia induced by excessive intake of calcium supplement, presenting similar findings of primary hyperparathyroidism.

A 31-year-old woman had ureterolithiasis related to hypercalcemia, and when she was admitted to our hospital ultrasonography and technetium-99 m sestamibi scintigraphy did not detect parathyroid abnormalities. Serum concentrations of calcium and intact parathyroid hormone were 9.7 mg/dl and 153 pg/ml, respectively, but subsequently increased to 13.5 mg/dl and decreased to 10 pg/ml, respectively. Diagnostic interview revealed that she had been taking excessive calcium supplements of 3,000 5,000 mg/day because she was worried about developing osteoporosis. Her hypercalcemia was cured after she stopped taking the supplements. The present case indicates that calcium supplementation of more than 2,500 mg/day elicits adverse effects on body mineral balance. Clear indications of the upper limits to supplements should be made known to the consumers.