Rationale: Coronary calcification is a frequent complication of end stage renal disease (ESRD) with recent estimates of up to 80% of chronic hemodialysis patients exhibiting moderate to severe vascular calcification 1. Numerous clinical factors have been associated with the development of arterial calcification including hyperphosphatemia 2, diabetes mellitus 3 and calcium containing phosphate binders 4. More recently, the increased use of vitamin D analogues to treat secondary hyperparathyroidism has been implicated as a major contributor to vascular calcification among ESRD patients.