calcium phosphate product (Ca-P product)

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Reference interval

of importance in stage 5 kidney disease
high calcium phosphate product in plasma, increases risk of soft-tissue calcification (calciphylaxis)
calcium-phosphate product of > 55 (mg/dL)2 associated with acute or subacute calcification of vascular, cardiac, & other soft tissues
since many factors are involved in the genesis of soft-tissue calcification, no exact threshold for the calcium phosphate product predicts soft-tissue calcification
hypercalcemia, together with hyperphosphatemia, or each individually can be responsible for increased plasma calcium phosphate product
since serum phosphate levels in patients with chronic kidney disease are usually increased by more (from 3.5 mg/dL to 7 mg/dL) than serum calcium (from 9.5 mg/dL to 11 mg/dL, the relative importance of serum phophate levels in generating higher calcium phosphate product is greater than serum calcium levels
thus control of calcium phosphate product is best achieved by controlling levels of serum phosphate