From the Guidelines
Oral calcium supplementation is recommended for patients with hypocalcemia, with a daily dose of 1-2 grams of elemental calcium, as suggested by the studies 1. When managing hypocalcemia, it is essential to consider the patient's renal function and corrected serum calcium levels.
- For patients with a GFR of 30 ml/min per 1.73 m2 and corrected serum calcium levels below 8.5 mg/dl, elemental calcium 1 g/d is recommended, as stated in the guideline 1.
- Calcium carbonate and calcium citrate are preferred formulations, with calcium carbonate providing 40% elemental calcium and should be taken with food to enhance absorption, while calcium citrate contains 21% elemental calcium but can be taken without food.
- The total daily calcium intake should not exceed 2.0 g/day, as higher intake may lead to hypercalcemia, especially in patients with chronic kidney disease (CKD) 1.
- Vitamin D supplementation (800-1000 IU daily) should accompany calcium therapy to enhance intestinal calcium absorption.
- Patients should monitor for side effects, including constipation, bloating, and kidney stones, and calcium levels should be regularly checked until stable, then periodically thereafter.
- The underlying cause of hypocalcemia should always be identified and treated, as this determines the duration of supplementation. Key considerations for calcium supplementation include:
- Dose: 1-2 grams of elemental calcium daily
- Formulation: Calcium carbonate or calcium citrate
- Administration: With food for calcium carbonate, or without food for calcium citrate
- Monitoring: Regular checks of calcium levels and side effects
- Accompanying therapy: Vitamin D supplementation to enhance intestinal calcium absorption.
From the Research
Oral Calcium for Hypocalcemia
- Oral calcium supplementation is commonly used to treat chronic hypocalcemia, often in combination with vitamin D supplementation 2.
- The choice of calcium supplement form is important, with calcium carbonate and calcium citrate being the most common forms 3.
- Calcium carbonate is the most cost-effective form, but should be taken with a meal to ensure optimal absorption, while calcium citrate can be taken without food and is suitable for individuals with achlorhydria or those taking certain medications 3.
- The maximum dose of elemental calcium that should be taken at a time is 500 mg, and U.S. Pharmacopeia-verified calcium supplements meet rigorous manufacturing and quality requirements 3.
- Potential adverse effects of calcium supplementation include gastrointestinal complaints, and high calcium intakes (>1500 mg/d) have been associated with an increased risk of advanced and fatal prostate cancer 3.
- In the treatment of hypocalcemia, oral calcium supplementation is often used in conjunction with other therapies, such as vitamin D supplementation and, in some cases, recombinant human parathyroid hormone (rhPTH) therapy 2.