What is calcium carbonate prescribed for?

From the Guidelines

Calcium carbonate is primarily prescribed as a calcium supplement to prevent or treat calcium deficiency and related conditions like osteoporosis, and as an antacid to relieve symptoms of acid reflux, heartburn, and indigestion. The typical doses for calcium supplementation range from 500-1200 mg of elemental calcium daily, often divided into smaller doses for better absorption, as seen in studies such as 1 and 1. When used as an antacid, it's usually taken as needed in doses of 500-1000 mg.

Key Considerations

• Calcium carbonate should be taken with food to enhance absorption and reduce gastrointestinal side effects like constipation or gas, as noted in 1.
• People with certain conditions like kidney stones, hypercalcemia, or those taking specific medications should consult healthcare providers before using calcium carbonate, as it may interact with some drugs by affecting their absorption, a consideration highlighted in 1 and 1.
• The choice between calcium carbonate and other calcium supplements like calcium citrate depends on factors such as the presence of gastrointestinal symptoms and the need for gastric acidity for absorption, as discussed in 1.

Dosage and Administration

• For calcium supplementation, the dose should be based on the amount of elemental calcium, with common preparations including purified calcium carbonate, calcium citrate, calcium lactate, and calcium gluconate, as outlined in 1.
• If daily supplementation with more than 500 mg of elemental calcium is required, divided doses are recommended to improve absorption and minimize gastrointestinal side effects, a recommendation supported by 1.

Special Populations

• In patients with chronic kidney disease (CKD), the use of calcium-containing phosphate binders should be limited by the maximally acceptable total oral and enteral calcium intake, as guided in 1 and 1.
• For children with CKD, calcium intake should be carefully managed to avoid both hypo- and hypercalcemic episodes, with consideration of dietary sources, phosphate binders, and dialysate calcium concentration, as discussed in 1 and 1.

From the Research

Calcium Carbonate Prescriptions

• Calcium carbonate is prescribed for various conditions, including:
  • Bone health in children, young adults, and menopausal women 2
  • Osteoporosis 3
  • Non-ulcer dyspepsia and minor episodes of heartburn (gastro-oesophageal reflux disease) 3
  • Calcium deficiency 4
• It is also used as an antacid to neutralize gastric hydrochloric acid and inhibit the proteolytic enzyme, pepsin 3
• Calcium carbonate can be used as a dietary phosphate binder in patients with chronic renal failure 3

Administration and Absorption

• Calcium carbonate should be taken with a meal to ensure optimal absorption 2, 5
• The maximum dose of elemental calcium that should be taken at a time is 500 mg 2
• Inhibition of gastric acid secretion does not affect calcium absorption after calcium carbonate compound granules, but moderately decreases it after traditional calcium carbonate preparations 4

Potential Adverse Effects

• Potential adverse effects of calcium supplementation include gastrointestinal complaints 2
• Renal calculi in most studies have not been associated with calcium supplementation, but high doses of calcium carbonate can cause hypercalcaemia and renal impairment 2, 6
• Calcium-alkali syndrome is a potential risk of long-term ingestion of calcium carbonate antacids, particularly if taken in high doses or with other medications that exacerbate hypercalcaemia 6