Hypocalcaemia

Causes

Appropriate Tests

 

Calcium, Albumin, Calcium (corrected), Phosphate.

Calcium (ionised), if indicated. Hypocalcaemia is only significant clinically if ionised calcium is reduced.

Low total, corrected, and ionised calcium:

 

  • Artefactual

Collection in EDTA, citrate or oxalate anticoagulant will result in a spurious reduction in calcium.

See Table 1.

  • Renal failure - chronic

 

  • Hypoparathyroidism

 

  • Vitamin D deficiency

See under Osteomalacia.

  • Hypomagnesaemia

 

  • Rhabdomyolysis

See under Myoglobinuria.

Low total calcium, normal corrected and ionised calcium:

 

  • Hypoalbuminaemia

 

Normal total and corrected calcium, low ionised calcium:

 

  • Hyperventilation