The purpose of this research study is to study the effects of paricalcitol on endothelial function and inflammation, cardiovascular risk factors which are associated with patient populations that have Type 2 diabetes and Stage 3 and 4 Chronic Kidney Disease (CKD).

Hypothesis 1: The state of CKD is associated with oxidative stress and inflammation and impaired post ischemic endothelium dependent flow mediated vasodilation which may contribute to atherogenesis.

Hypothesis 2: The administration of paracalcitol to patients with CKD will suppress oxidative stress and inflammation and improve endothelial function and thus contribute to an anti-atherogenic action.

Inclusion Criteria:

1. Patients with Type 2 diabetes and CKD
2. Age 18 - 70 years
3. Stable anti-hypertensive and lipid lowering therapy for at least 2 months. All patients should be on an ACEI or ARB unless contraindicated because of side effects (standard of care). No changes in lipid lowering therapy during the 3 months of this study. Blood pressure doses may be changed but new therapy with ACE inhibitors will not be allowed.

Exclusion Criteria:

1. Severe co morbid conditions - e.g. Cancer, etc.
2. Congestive heart failure.
3. Inability to give informed consent or attend study related visits.
4. Have a history of abnormally high vitamin D or calcium levels in the bloodstream.
5. Unwilling or unable to complete screening or data collection procedures.
6. Have a known allergy to the study drug.
7. Pregnant or breast feeding
8. Plasma Calcium >9 mg/dl
9. Patients should discontinue any calcium supplementation prior to entry into the study.
10. Other vitamin D analogs (eg Sensipar) and vitamin D preparations are contraindicated