Normal Range: 2·2 to 2·6mmol/L

These guidelines do not apply to critically ill patients or to patients at risk of refeeding syndrome. For refeeding syndrome please see Policy for prevention and management of refeeding syndrome in adults

  • If cause for hypocalcaemia is not clear then further diagnostic tests such as Parathyroid Hormone (PTH) need to be taken before treatment. PTH and corrected calcium levels should be taken simultaneously prior to treatment.
  • Stable patients with mild symptoms may not require supplementation.


  • magnesium deficiency – if present, correction of this may be sufficient to correct calcium
  • parathyroidectomy (see page 8)
  • thyroidectomy
  • hypothyroidism
  • insufficient calcium intake or absorption (especially post gastrectomy)
  • acute pancreatitis
  • chronic kidney disease
  • vitamin D deficiency
  • hyperphosphataemia
  • hypoalbuminaemia
  • drugs – aminoglycosides, furosemide, phenobarbital, phenytoin, methylprednisolone, desferrioxamine, phosphate enemas, bisphosphonates

Clinical Features

  • numbness and tingling of hands
  • irritability, anxiety
  • fatigue
  • carpopedal spasm
  • muscle cramps and tetany
  • bronchospasm
  • laryngeal spasm
  • convulsions
  • prolonged QT interval, leading to ventricular fibrillation (VF) or heart block

Hypocalcaemia Treatment Regime

Via enteral feeding tube*: dissolve tablet(s) in 30 to 50mL water. Stopping feed is not required. Give oral calcium supplements outwith mealtimes. Consider alfacalcidol if patient has renal failure. THEN Intravenous (IV) 50mL (11·25mmol) calcium gluconate 10% injection given in 500mL sodium chloride 0.9% or glucose 5% infusion over 4 hours. Further bolus doses of calcium may be required after the infusion depending on symptoms and plasma calcium and magnesium levels.

Adjusted Calcium Level Action Monitor
2·0 to 2·25mmol/L Oral: Calvive (formerly called Sandocal), 1 to 2 tablets (25 to 50mmol calcium) daily. Recheck adjusted calcium after 24 hours. 
Less than 2·0mmol/L IV 50mL (11·25mmol) calcium gluconate 10% in 500mL sodium chloride 0.9% or glucose 5% infusion over 4 hours.  Recheck adjusted calcium 60 minutes after end of infusion.
Hypocalcaemic tetany  10mL (2·25mmol) calcium gluconate 10% injection given as an IV bolus over 5 minutes Recheck adjusted calcium and magnesium levels 60 minutes after end of infusion.  

All infusions must be administered via an infusion pump.

ECG monitoring generally not required unless hypocalcaemic tetany is evident (see below) or patient is taking digoxin, due to interaction with calcium.

  • Calcium is irritant to tissues (less irritant the more it is diluted). Regular checks should be made for evidence of extravasation. Check venflon is in a large vein and working well and that the infusion is running well before and during administration of IV calcium.
  • Calcium gluconate 10% injection = 2·25mmol calcium/10mL.
  • Patients with more severe hypocalcaemia may need oral supplements of oral calcium and/or alfacalcidol as well as IV treatment to prevent calcium deficiency returning.
  • *Note that absorption may be reduced if administered via jejunal feeding tube.

Last reviewed: 28/04/2022

Next review date: 28/04/2025

Author(s): Renal Department .

Approved By: TAM Subgroup of ADTC

Reviewer name(s): Dr S Lambie, Consultant.

Document Id: TAM289