Disorders of calcium metabolism

Disorders of calcium metabolism occur when the body has too little or too much calcium. The serum level of calcium is closely regulated within a fairly limited range in the human body.

The amount of biologically active calcium varies with the level of serum albumin, a protein to which calcium is bound, and therefore levels of ionized calcium are better measures than a total calcium; however, one can correct a total calcium if the albumin level is known.

• A normal ionized calcium is 1.12-1.45 mmol/L (4.54-5.61 mg/dL).
• A normal total calcium is 2.2-2.6 mmol/L (9-10.5 mg/dl).
  • Total calcium of less than 8.0 mg/dL is hypocalcaemia, with levels below 1.59 mmol/L (6 mg/dL) generally fatal.
  • Total calcium of more than 10.6 mg/dL is hypercalcaemia, with levels over 3.753 mmol/L (15.12 mg/dL) generally fatal.

See also

• calcium metabolism
• Pseudohypoparathyroidism
• Milk-alkali syndrome