RT Book, Section
A1 Sprague, Stuart M.
A2 Lerma, Edgar V.
A2 Rosner, Mitchell H.
A2 Perazella, Mark A.
SR Print(0)
ID 1149111999
T1 Disorders of Calcium Metabolism: Hypocalcemia and Hypercalcemia
T2 CURRENT Diagnosis & Treatment: Nephrology & Hypertension, 2e
YR 2017
FD 2017
PB McGraw-Hill Education
PP New York, NY
SN 9781259861055
LK accessmedicine.mhmedical.com/content.aspx?aid=1149111999
RD 2024/04/20
AB Serum  calcium  concentrations  are  normally  tightly  controlled  within  a  narrow  range,  usually  8.5–10.5  mg/dL.  However,  the  serum  calcium  concentration  comprises  less  than  1%  of  the  total  body  calcium  content  and  is  a  poor  reflection  of  overall  total  body  calcium.  The  remainder  of  total  body  calcium  is  stored  in  bone.  Serum  calcium  concentration  comprises  ionized  calcium  (approximately  40%),  which  is  physiologically  active,  while  the  remainder  of  the  calcium  is  bound  predominantly  to  albumin  (approximately  45%)  and  to  a  much  lesser  extent  to  anions  (approximately  15%)  such  as  citrate,  bicarbonate,  and  phosphate.  In  the  presence  of  acidosis,  there  is  a  relative  increase  in  the  ionized  calcium  component  of  the  total  serum  calcium.  Serum  levels  of  ionized  calcium  are  maintained  in  the  normal  range  by  the  secretion  of  parathyroid  hormone.