In individual patients, a diagnosis of CSS was ascertained based on the presence of hypercalcemia (normal range 8.5–10.1 mg/dL), a normal or suppressed PTH level (normal range 10–65 pg/mL), renal insufficiency with elevated serum creatinine (normal range 0.6–1.3 mg/dL), and metabolic alkalosis with elevated serum bicarbonate (normal range 21–32 mmol/L), and supported by a history of prescription or over-the-counter intake of calcium. Here, PTH is linked to Renal insufficiency.