1. Section of Endocrinology (R.N.C., F.E.W.) Department of Medicine University of Chicago Chicago, Illinois 60637
2. Thyroid Unit (S.B., B.K., A.N.H.) Division of Endocrinology and Division of Bone, Massachusetts 02215
3. Mineral Metabolism (M.C.) Beth Israel Deaconess Medical Center Boston, Massachusetts 02215