The purpose of this study is to determine the value the additional antiproteinuric effects of vitamin D derivatives treatment, in patients with Chronic Kidney Illness phase II-IV, with lack of vitamin D and residual proteinuria higher 0,5 grams/day.

Inclusion Criteria:

• Male/female Patients older 18 years old
• Patients have signed written informed consent
• Chronic Kidney Illness phase II-IV plus residual proteinuria >0,5 grams/day (two or more consecutive occasions) and plus beta blockers treatment from AARS during al least 3 months.
• Serum levels of calcifediol in the lack of level (15-30 ng/ml).

Exclusion Criteria:

• Bad control of high blood pressure (higher or same 180/110 mmHg)
• Bad control of diabetes (HbA1c higher 9,5 in the last three months period)
• Hypercalcemia (<10,2 mg/dL) o hyperphosphatemia(>5,5 mg/dL), CaxPO4>50, hypercalciuria (urin Ca/Cr quotient > 0,15)
• Vitamin D treatment or any analogous
• Hepatic failure ( AST o ALT > 3 times higher than normal limit)
• medical history of poor nutrient intestinal absorptions or chronic diarrhea
• Active nephrolithiasis
• Treatment with medication wich can change vitamin D metabolism (phenobarbital, phenytoin, rifampicin)
• Participation in other Clinic Trial in 3 last months
• Active Alcoholism
• Neoplasia precedent (except cutaneous no melanoma)
• Pregnant women or while breastfeeding
• Vitamin D hypersensitivity or any its excipient hypersensitivity
• Any other condition from Research