Patient description: The patient is a 25-year-old man with type 1 diabetes confirmed with molecular analysis 7 years ago. He presents to the clinic with shortness of breath and fatigue during activities. He claims mild dyspnea after climbing 3 floors, no dyspnea at rest and no angina (New York Heart Association class 2). He is diagnosed with cardiomyopathy that will be treated with ACE inhibitors and Beta blockers. His takes 70/30 Insulin and vitamin D supplements. His past medical history is not significant for any other medical issues. His family history is positive for DM type 1 in his uncle and his grandfather. His lab study is as bellow: FBS: 100 mg/dl HbA1c: 6.5% Cholesterol: 190 mg/dl TG: 140 mg/dl LDL: 125 mg/dl HDL: 40 mg/dl

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Heart Failure Sign informed consent Willing and able to adhere to all study-related procedures, including study medication regimen ≥ 18 years old Previous clinical diagnosis of heart failure with preserved ejection fraction: NYHA Class II-IV Satisfy these echocardiographic within the last year: Left ventricular ejection fraction ≥ 50%, cardiac magnetic resonance or ventriculogram; Left atrial size ≥ 4 cm in long axis or > 5.2 cm in four chamber length; Septal wall thickness > 1.2 cm (females) or 1.3 cm (males); Doppler evidence of moderate or severe diastolic dysfunction (≥ Grade II) by transmitral inflow, pulmonary venous flow, color M-mode and/or tissue Doppler (per European Society of Cardiology guidelines) Experienced ≥ 1 of the following in last 12 months: Hospitalization for acute heart failure (primary diagnosis); Long term treatment with loop diuretic; Mean pulmonary capillary wedge pressure ≥ 16 mm Hg at catheterization for dyspnea; Left ventricular end diastolic pressure (LVEDP) ≥ 19 mm Hg at catheterization for dyspnea; Acute treatment with intravenous loop diuretic or hemofiltration On stable medical therapy in last 30 days before study entry (defined as no change in angiotensin converting enzyme inhibitors [ACEI], angiotensin receptor blockers, aldosterone inhibitors, beta-blockers or calcium channel blockers Satisfy these at initial lab screening: Estimated glomerular filtration rate (eGFR) ≥ 30 ml/min; Corrected serum Ca 8.0-10.0 mg/dL (2.0-2.5 mmol/L); Phos ≤ 5.2 mg/dL (1.68 mmol/L); Serum albumin ≥ 3.0 g/dL (30 g/L) Negative serum pregnancy test for females of childbearing potential (within 2 weeks of starting study treatment) Women of childbearing potential must be practicing barrier/oral contraception during study-related treatment, or be surgically sterile or one year post-menopausal, be non-nursing and non-pregnant  Taking > 1,000 IU of vitamin D preparation daily within last 30 days Received activated vitamin D preparation including paricalcitol (Zemplar®), doxercalciferol (Hectorol®) or calcitriol (Rocalctrol®, Calcijex®) within last 90 days prior to study entry History of nephrolithiasis Poorly controlled hypertension (systolic blood pressure > 180 mmHg and/or diastolic blood pressure > 110 mmHg at Screening; confirmed by repeat) Secondary hypertension (i.e. renal artery stenosis, primary aldosteronism or pheochromocytoma) Severe hepatic impairment Use of known inhibitors (ie, ketoconazole) or inducers (ie, carbamazepine) of cytochrome P450 3A (CYP3A) within 2 weeks prior to taking study drug HIV positive Condition with prognosis < 1 year at study entry other than heart failure Significant valvular disease defined as moderate or severe aortic or mitral stenosis, mitral or aortic regurgitation