From the Guidelines
The best oral medication for treating hypocalcemia is calcium carbonate, taken in doses of 500-1000 mg elemental calcium 2-3 times daily. For optimal absorption, it is recommended to take calcium carbonate with food, split doses throughout the day, and combine with vitamin D3 (1000-2000 IU daily) to enhance absorption 1. A complete regimen might look like:
- Calcium carbonate 500 mg with breakfast
- Calcium carbonate 500 mg with dinner
- Vitamin D3 1000 IU daily Calcium carbonate is preferred because it's inexpensive, widely available, and contains a high percentage of elemental calcium (40%) 2. It's best absorbed in an acidic environment, which is why it should be taken with food. Splitting doses improves absorption, as the body can only absorb about 500 mg of calcium at a time. Vitamin D is crucial for calcium absorption in the intestines and helps maintain proper calcium levels in the blood. If calcium carbonate causes gastrointestinal side effects, calcium citrate can be used as an alternative, though it contains less elemental calcium (21%) and may require higher doses. The American College of Rheumatology recommends optimizing calcium intake (1,000–1,200 mg/day) and vitamin D intake (600–800 IU/day) for all patients receiving glucocorticoid treatment 1, 2.
From the Research
Oral Medications for Treating Hypocalcemia
- The best oral medication for treating hypocalcemia is not explicitly stated in the provided studies, as they primarily focus on calcium supplementation for bone health and osteoporosis prevention.
- However, the studies suggest that calcium carbonate and calcium citrate are the most common and effective forms of calcium supplements 3, 4, 5, 6, 7.
- Calcium carbonate is generally considered the most cost-effective form and should be taken with a meal to ensure optimal absorption 3, 5.
- Calcium citrate, on the other hand, can be taken without food and is recommended for individuals with achlorhydria or those taking histamine-2 blockers or protein-pump inhibitors 3, 6, 7.
- The maximum dose of elemental calcium that should be taken at a time is 500 mg, and calcium intakes up to at least 62.5 mmol (2500 mg) are considered safe for virtually all patients 3, 4.
Considerations for Calcium Supplementation
- A divided dose regimen (e.g., 2-3 times a day) may result in substantially greater absorption of a supplement than a single daily dose 4, 5.
- Gastric acid is not necessary for absorption of calcium supplements, as long as they are taken with meals 4, 6.
- Vitamin D supplementation is also important for bone health, and the combination of calcium and vitamin D is effective in reducing the incidence of non-vertebral and hip fractures 7.