Treatment of Hypocalcemia
The treatment of hypocalcemia should include calcium supplementation (oral or intravenous depending on severity), vitamin D supplementation, and correction of any underlying causes, with treatment decisions based on symptom severity and serum calcium levels. 1
Assessment and Diagnosis
- Check serum calcium levels (normal corrected range: 8.4-9.5 mg/dL or 2.10-2.37 mmol/L)
- Measure ionized calcium (normal range: 1.1-1.3 mmol/L)
- Assess for symptoms:
- Neuromuscular irritability
- Tetany
- Chvostek's and Trousseau's signs
- Seizures
- Cardiac arrhythmias (prolonged QT interval)
- Bronchospasm and laryngospasm
- Check 25-hydroxyvitamin D levels (target >30 ng/mL)
- Evaluate for underlying causes (hypoparathyroidism, vitamin D deficiency, chronic kidney disease, etc.)
Treatment Algorithm
1. Severe Symptomatic Hypocalcemia
- Intravenous calcium administration 2, 3
- Calcium gluconate: preferred for peripheral IV access
- Initial dose: 1-2 g calcium gluconate (93-186 mg elemental calcium)
- Administer slowly at maximum rate of 200 mg/minute in adults or 100 mg/minute in pediatric patients
- Monitor ECG during administration
- For continuous infusion: dilute to 5.8-10 mg/mL in 5% dextrose or normal saline
2. Chronic or Mild-Moderate Hypocalcemia
Oral calcium supplementation 1, 4
- Calcium carbonate: 1000-2000 mg elemental calcium daily in divided doses
- Calcium carbonate preferred due to higher elemental calcium content
- Consider calcium chloride solution in patients with achlorhydria who are refractory to calcium carbonate 5
Vitamin D supplementation 1
- Cholecalciferol (vitamin D3): 800-1000 IU daily for general supplementation
- For vitamin D deficiency: ergocalciferol (vitamin D2) or higher doses of cholecalciferol
- For hypoparathyroidism: active vitamin D metabolites (calcitriol) may be required
3. Special Considerations
For Chronic Kidney Disease Patients
- Use an individualized approach to correct only significant or symptomatic hypocalcemia 6
- Avoid aggressive calcium replacement due to risk of positive calcium balance
- Maintain calcium-phosphorus product <55 mg²/dL² 1
- Monitor for hypercalciuria with urinary calcium measurement
For Hypoparathyroidism
- Calcium and vitamin D supplementation must be carefully titrated 4
- Target serum calcium in low-normal range to minimize hypercalciuria
- Consider recombinant human PTH(1-84) for refractory cases 4
Monitoring
- For IV calcium administration: monitor serum calcium every 4-6 hours during intermittent infusions and every 1-4 hours during continuous infusion 2
- For chronic management: check serum calcium and phosphorus every 3 months 1
- Increase monitoring during periods of biological stress (surgery, childbirth, infection) 1
- Monitor for signs of overcorrection, which can lead to hypercalcemia, renal calculi, and renal failure 6, 1
Important Precautions
- Administer IV calcium via secure intravenous line to avoid calcinosis cutis and tissue necrosis 2
- Do not mix calcium gluconate with ceftriaxone (contraindicated in neonates) 2
- Avoid alcohol and carbonated beverages in patients prone to hypocalcemia 6
- For patients with hypocalcemia due to 22q11.2 deletion syndrome, monitor calcium levels during biological stress (surgery, childbirth, infection) 6
- In patients receiving calcimimetics (cinacalcet), mild to moderate hypocalcemia may not require aggressive correction 6, 1
By following this structured approach to hypocalcemia management based on symptom severity and underlying causes, clinicians can effectively treat this potentially serious electrolyte disorder while minimizing complications.