RT Book, Section
A1 Khosla, Sundeep
A2 Loscalzo, Joseph
A2 Fauci, Anthony
A2 Kasper, Dennis
A2 Hauser, Stephen
A2 Longo, Dan
A2 Jameson, J. Larry
SR Print(0)
ID 1197685087
T1 Hypercalcemia and Hypocalcemia
T2 Harrison's Principles of Internal Medicine, 21e
YR 2022
FD 2022
PB McGraw-Hill Education
PP New York, NY
SN 9781264268504
LK accessmedicine.mhmedical.com/content.aspx?aid=1197685087
RD 2024/04/19
AB The  calcium  ion  plays  a  critical  role  in  normal  cellular  function  and  signaling,  regulating  diverse  physiologic  processes  such  as  neuromuscular  signaling,  cardiac  contractility,  hormone  secretion,  and  blood  coagulation.  Thus,  extracellular  calcium  concentrations  are  maintained  within  an  exquisitely  narrow  range  through  a  series  of  feedback  mechanisms  that  involve  parathyroid  hormone  (PTH)  and  the  active  vitamin  D  metabolite  1,25-dihydroxyvitamin  D  [1,25(OH)2D].  These  feedback  mechanisms  are  orchestrated  by  integrating  signals  between  the  parathyroid  glands,  kidney,  intestine,  and  bone  (Fig.  54-1;  Chap.  409).  Disorders  of  serum  calcium  concentration  are  relatively  common  and  often  serve  as  a  harbinger  of  underlying  disease.  This  chapter  provides  a  brief  summary  of  the  approach  to  patients  with  altered  serum  calcium  levels.  See  Chap.  410  for  a  detailed  discussion  of  this  topic.