NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated July 13, 2026

Calcium Carbonate

Prescription ·Exploratory record · not publication-reviewed ·Updated July 13, 2026

A widely used over-the-counter antacid that provides rapid, short-term relief of heartburn, acid indigestion, and sour stomach. Calcium carbonate also serves as a calcium supplement and is used as a phosphate binder in patients with chronic kidney disease.

Evidence tier
Moderate
Indexed sources
10 1999–2025
Interactions
0
Depletes
3 nutrients
Read the sources → Compare profiles
Publication status

Exploratory record, not a reviewed medical publication.

See the editorial and medical-review policies for the publication gate.

This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.

In short

What the research says.

A quick, data-only summary. The full evidence, dosing, and sources are below.

A widely used over-the-counter antacid that provides rapid, short-term relief of heartburn, acid indigestion, and sour stomach. NutriStack rates the supporting evidence as moderate. Common adult dosing is 500–1500 mg as needed for symptoms, up to 7500 mg/day; calcium supplement: 500–600 mg per dose (as prescribed by your physician), though a prescriber sets the actual dose. With long-term use it can deplete iron, vitamin b12, folate. This profile indexes 10 sources.

What it's good for
  • Rapid relief of heartburn and acid indigestion6
  • Supplemental calcium for bone health2,5
  • Phosphate binding in chronic kidney disease9,5
  • Relief of sour stomach and dyspepsia
What to watch for
  • Constipation
  • Acid rebound with chronic use
  • Hypercalcemia (with excessive use)
  • Hypercalcemia
  • Renal calculi (calcium-containing stones)1,2

The bottom line

Evidence rating moderate. Most-documented uses: rapid relief of heartburn and acid indigestion, supplemental calcium for bone health, phosphate binding in chronic kidney disease. 10 sources indexed (1999–2025), with 0 interaction records on file.

The science

How it works, mechanistically.

Core mechanism

Directly neutralizes gastric hydrochloric acid in the stomach lumen, raising intragastric pH. The calcium ion also stimulates gastrin release, which can cause a secondary acid rebound effect. Each gram of calcium carbonate neutralizes approximately 20 mEq of acid.6

Class
Antacid
Absorption
Water-soluble; take with food
Dosing

Dosing & protocol.

Common range
500–1500 mg as needed for symptoms, up to 7500 mg/day; calcium supplement: 500–600 mg per dose (as prescribed by your physician)
Recommended form
Chewable tablet or oral suspension

Best absorbed when taken with food; chew tablets completely before swallowing8,4

Depletions

What it depletes.

Nutrients this medication can lower over time, and what to replace.

Iron

Mild

Calcium carbonate can reduce non-heme iron absorption by competing during intestinal uptake and by buffering gastric acidity.

Replace Iron BisglycinateMonitor Ferritin + transferrin saturationOnset Usually with repeated co-administration

Vitamin B12

Mild

Chronic acid buffering can reduce release of food-bound B12 from dietary proteins.

Replace MethylcobalaminMonitor Serum B12 + methylmalonic acidOnset Usually with chronic use

Folate

Mild

Chronic acid buffering can modestly reduce folate absorption in some users.

Replace MethylfolateMonitor Serum folate or RBC folateOnset Usually with chronic use

Full Calcium Carbonate depletion and interaction guide →

Safety

Full safety detail.

Side effects

  • Constipation
  • Acid rebound with chronic use
  • Hypercalcemia (with excessive use)
  • Milk-alkali syndrome (rare, with high doses)
  • Belching
  • Flatulence

Contraindications

  • Hypercalcemia
  • Renal calculi (calcium-containing stones)1,2
  • Severe renal impairment (without medical supervision)6
  • Hypophosphatemia
Sources

Sources, by evidence tier.

Numbered references. Citations throughout the page link here.

Meta-analyses & systematic reviews

3

Randomized controlled trials

2

Reviews & position papers

1

Reference material

4
FAQ

Common questions.

Quick answers about Calcium Carbonate, drawn from the data on this page.

What is Calcium Carbonate?

A widely used over-the-counter antacid that provides rapid, short-term relief of heartburn, acid indigestion, and sour stomach. Calcium carbonate also serves as a calcium supplement and is used as a phosphate binder in patients with chronic kidney disease.

What is Calcium Carbonate used for?

Commonly cited benefits of Calcium Carbonate include: Rapid relief of heartburn and acid indigestion; Supplemental calcium for bone health; Phosphate binding in chronic kidney disease; Relief of sour stomach and dyspepsia. NutriStack rates the overall evidence as moderate.

What is a typical dose of Calcium Carbonate?

A typical adult dose of Calcium Carbonate is 500–1500 mg as needed for symptoms, up to 7500 mg/day; calcium supplement: 500–600 mg per dose (as prescribed by your physician). The commonly recommended form is Chewable tablet or oral suspension. These are general ranges, not personalized advice; confirm the right dose with a clinician.

What are the side effects of Calcium Carbonate?

Reported side effects include constipation, acid rebound with chronic use, hypercalcemia (with excessive use), milk-alkali syndrome (rare, with high doses), belching, flatulence. This is educational information; check with a healthcare professional before use.

How strong is the evidence for Calcium Carbonate?

NutriStack rates this as Moderate, meaning several aligned RCTs or one large RCT plus supporting reviews. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.

Use this with your stack

Calcium Carbonate in NutriStack.

Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.

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NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.