From the Guidelines
The recommended dose of calcium phosphate for treating hypocalcemia is 1,000-2,000 mg of elemental calcium per day, divided into multiple doses to improve absorption, with individualized dosing based on serum calcium levels, symptom severity, and underlying causes of hypocalcemia.
Key Considerations
- For acute symptomatic hypocalcemia, intravenous calcium gluconate (10%) is typically preferred at 1-2 grams (10-20 mL) administered slowly over 10-20 minutes, which can be repeated as needed 1.
- Oral supplementation with calcium phosphate products typically provide 250-500 mg of elemental calcium per dose, taken 2-4 times daily 1.
- Calcium phosphate is particularly useful when patients also have hypophosphatemia, as it addresses both deficiencies simultaneously 1.
Monitoring and Adjustment
- Treatment should be monitored with regular blood tests to assess calcium levels and adjust dosing accordingly 1.
- Calcium supplements are best absorbed when taken with food and in divided doses rather than as a single large dose 1.
Special Considerations
- In patients with chronic kidney disease (CKD), treatment should focus on patients with hyperphosphatemia, and prevention rather than treatment of hyperphosphatemia may be valuable in patients with CKD stage G3a to G5D 1.
- Higher serum calcium concentrations have been linked to increased mortality and nonfatal cardiovascular events in adults with CKD, emphasizing the need for careful dosing and monitoring 1.
From the Research
Dose of Calcium Phosphate for Treating Hypocalcemia
The provided studies do not directly address the dose of calcium phosphate for treating hypocalcemia. However, they do discuss the treatment of hypocalcemia with calcium gluconate and other forms of calcium.
- The studies 2, 3 evaluate the efficacy of calcium gluconate in treating hypocalcemia in critically ill patients.
- Study 2 found that 1-2 g of IV calcium gluconate was effective in normalizing ionized serum calcium (iCa) for patients with mild hypocalcemia, while 2-4 g was effective for some patients with moderate to severe hypocalcemia.
- Study 3 found that an infusion of 4 g of calcium gluconate was effective in increasing serum iCa in critically ill patients with moderate to severe hypocalcemia.
- Study 4 discusses the use of recombinant human teriparatide in treating severe hypocalcemia in patients with postoperative hypoparathyroidism, but does not provide information on calcium phosphate dosing.
- Study 5 reviews calcium regulation and the treatment of hypocalcemia in critically ill patients, but does not specify a dose of calcium phosphate.
- Study 6 discusses the use of oral calcium chloride in a patient with hypoparathyroidism refractory to treatment with calcium carbonate and vitamin D, but does not provide information on calcium phosphate dosing.
Alternative Forms of Calcium
While the studies do not provide direct information on calcium phosphate dosing, they do suggest that other forms of calcium, such as calcium gluconate and calcium chloride, can be effective in treating hypocalcemia.
- Calcium gluconate is commonly used to treat hypocalcemia in critically ill patients, with doses ranging from 1-4 g IV 2, 3.
- Calcium chloride can be used to treat hypocalcemia in patients who are refractory to treatment with calcium carbonate and vitamin D, with a dose of 1.09 gm of elemental Ca given orally every 8 hours 6.