<unk>  occur when the body has too little or too much<unk> . The serum level of<unk>  is closely regulated within a fairly limited range in the human body.
The amount of biologically active<unk>  varies with the level of serum albumin, a protein to which<unk>  is bound, and therefore levels of ionized<unk>  are better measures than a total<unk> ; however, one can correct a total<unk>  if the albumin level is known.
A normal ionized<unk>  is 1.12-1.45  mmol/L (4.54-5.61 mg/dL).
A normal total<unk>  is 2.2-2.6 mmol/L (9-10.5 mg/dl).
Total<unk>  of less than 8.0 mg/dL is hypocalcaemia, with levels below 1.59 mmol/L (6 mg/dL) generally fatal.
Total<unk>  of more than 11.111 mg/dL is hypercalcaemia, with levels over 3.753 mmol/L (15.12 mg/dL) generally fatal.
Total<unk>  of less than 8.0 mg/dL is hypocalcaemia, with levels below 1.59 mmol/L (6 mg/dL) generally fatal.
Total<unk>  of more than 11.111 mg/dL is hypercalcaemia, with levels over 3.753 mmol/L (15.12 mg/dL) generally fatal.
Disorders of calcium metabolism
Tumor induced osteomalacia
Vitamin D deficiency
Primary lymphoma of the bone
Metastatic calcification
Dystrophic calcification
Plasma cell disorder
Molybdenum cofactor deficiency