1. Division of Mineral Metabolism, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
2. Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
3. Department of Clinical Sciences, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
4. Division of Nephrology, Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
5. Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas