High P LOW Ca

A potential complication of calcium therapy is that absorption of some of the administered calcium may promote the development of coronary arterial calcification, which is postulated to be associated with coronary atherosclerosis [34,35]. To help decrease this possibility, the working group for the K/DOQI guidelines suggest that the total dose of elemental calcium (including dietary sources) should not exceed 2000 mg/day [21]. In addition, with the recommended upper limit of plasma calcium of 9.5 mg/dL (2.35 mmol/L), the amount of elemental calcium is usually also reduced to no more than 1500 mg/day. Even these doses of calcium result in positive calcium balance in the setting of vitamin D therapy, which may have untoward long-term consequences. (See "Active vitamin D analogs and calcimimetics to control hyperparathyroidism in chronic kidney disease" and see "Vascular calcification in chronic kidney disease").