150 adult subjects (\> 21 years of age, any cause of CKD) of either gender of any ethnicity with CKD Stage V on hemodialysis will be recruited from Davita-UTSW dialysis centers and randomized into two equal groups in a parallel design, stratified according to gender and age (\> or ≤ 50 years). After baseline evaluation, one group (EffCaMgCit Group) will take EffCaMgCit, and the other group (CaAcS Group) will take calcium acetate suspension/solution for two years. Both drugs will be taken 1 sachet each just before or along with breakfast and dinner for the first three months. If tolerated, the dose will be increased to 1 sachet tid just before or along with breakfast, lunch and dinner.
After screening and a baseline evaluation, research personnel will visit patients at the dialysis center every three months for two years. Patients will be evaluated with a medical history, side effect questionnaires, blood pressure measurements, blood tests, echocardiograms, coronary artery calcification analyses, muscle magnesium analyses, and bone mineral density analyses.
It is expected that markers of cardiovascular risk would be improved in patients taking CaMgCit, and would remain stable in those taking CaAcS.
Endpoint Expectations:
* During treatment with EffCaMgCit, T50 would increase (indicative of reduced propensity for CPP formation)
* Serum Mg (inhibitor of CPP formation) would be increased by EffCaMgCit
* An increase in intracellular muscle Mg would show that EffCaMgCit provides a Mg load, and also indicates repletion of Mg stores that might be cardioprotective independently of effects on CPP formation
* The Investigators anticipate that serum FGF23 would be lower and serum Klotho would be higher on EffCaMgCit
