Effects of Cholecalciferol Supplementation in Patients With Chronic Heart Failure and LOw vITamind D Levels

Inclusion Criteria: * Heart failure diagnosis according to European Society of Cardiology Guideline criteria * Age \> 60 years old * 25(OH) Vitamin D level \< 30 ng/ml * Clinical and therapeutic stability for one month (NYHA class II or III) Exclusion Criteria: * Chronic use of anticonvulsants or barbiturates, steroids, thiazides, aluminium or magnesium, colestipol or cholestyramine * Glomerular filtration rate lower than 30 ml/min/1.73 m2 according to MDRD equation * Nephrolitiasis, Sarcoidosis or hypercalcemia * Recent (three months) acute coronary syndrome or stroke or major vascular surgery * Reduced life expectancy due to other diseases (active neoplasms, liver cirrhosis...)