To investigate whether treatment with a vitamin-D receptor activator is able to improve important markers of cardiovascular risk.

Main question:

May 12 weeks of VDRA treatment reduce the pathological sympathetic overactivation associated with moderate kidney disease?

Secondary questions aim to thrown light on how VDRAs can reduce albuminuria and CRP, i.e. does VDRA treatment improve (prespecified statistical analyses):

A) diastolic dysfunction? B) capillary microcirculation, and whether ameliorated disturbances relate to improved diastolic dysfunction? C) endothelial dysfunction and arterial stiffness? D) inflammatory activation? E) platelet function and haemostasis? F) levels of antibacterial peptides? G) levels of IGFBP-1 and adiponectin?

Overall design The study is designed as a double-blind, randomised, placebo-controlled trial involving two groups (n=72) of patients: 1) chronic kidney failure (CKD, eGFR 15-59 mL/m2) and 2) chronic kidney failure and concomitant diabetes mellitus (CKD+DM).

It will start with a two-week placebo run-in, followed by randomisation to:

1. Zemplar 1 μg (taken as 1 x 1 μg capsule and one placebo capsule),
2. Zemplar 2 μg (taken as 2 x 1 μg capsules) and
3. placebo (taken as two placebo capsules).

Inclusion Criteria:

eGFR 15-59 ml/m2

Exclusion Criteria:

Current vitamin D treatment