The Effects of Active VItamin D on Left Atrial Volume Index

This is a pilot feasibility study to determine the effects of an activated vitamin D compound (paricalcitol) on heart structure (size) and function (ability to relax) in patients with normal kidney function and a form of heart failure known as HFPEF (heart failure and preserved ejection fraction). This study will also examine heart failure-related hospitalizations and changes in cardiac-stretch and biological markers that are believed to change along with heart size. Patients in this pilot study will be treated for a period of 48 weeks with paricalcitol at a dose previously approved by FDA (1 mcg per day) and followed-up for 4 weeks after treatment is completed.