Supplement evidence

056 / 575Mineral form

Calcium carbonate

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The short answer

Provides calcium and also works as an antacid; it contains more elemental calcium by weight.

Evidence and scope: Established for an indicated use
This status does not grade the ingredient for every goal, outcome, or person.
Important limitation: The benefit is tied to the stated indication, dose, and population; it is not evidence of broader disease prevention or longer life.
Before deciding: Key concern: Acid-suppressing medicines can reduce absorption; separate thyroid medicine, iron, and antibiotics.

01 / PRACTICAL GUIDE

Dose, absorption, and combinations

These are indication-specific reference or studied ranges—not a personalized prescription. Start with the objective, then check the form, label, medicines, and health conditions.

Reference range by objective

Bone-health planUp to 500 mg elemental calcium per dose within the daily total

Reference or studied range—not a personalized prescription. The product label or a clinician may specify a different dose.

Dose source ↗

More is not automatically better. A clinician or product label may specify a different amount.

Absorption / solubilityFormulation-dependent

Not usefully classified as a fat- or water-soluble vitamin; absorption depends on the salt, extract, delivery system, and meal.

How it is commonly taken

Take with food because stomach acid improves absorption.

Do not combine casually

Acid-suppressing medicines can reduce absorption; separate thyroid medicine, iron, and antibiotics.

Dose and use source ↗

Dose and use links lead to primary or official source material. Search links are discovery tools, not proof that every returned paper applies.

02 / EVIDENCE

What the research says

We keep supportive, mixed, negative, safety, and contextual findings together. The headline never replaces the underlying papers.

2research papers in this ledger

2unique primary studies represented

2,390unique participants represented

These are audited counts for this JIVANA collection, not search-result totals. Participants are counted once when multiple papers use the same cohort; review papers are not added again to participant totals.

Open the research timelineResearch timeline

Entries are ordered by publication year. A study period appears only when the source reports it.

2008

Mixed or qualifiedPMID 18541589 · NCT00153816

Effect of calcium supplementation on fracture risk

Fractures were lower during treatment, but not after treatment ended. Fracture analysis was not the original trial purpose, event counts were small, and the selected adenoma population limits generalization.

Published: 2008Duration: 4 years of treatment; mean 10.8 years total follow-upn=930 participants

Study design and methods

Design: Randomized, double-blind, placebo-controlled secondary fracture analysis
Population: 930 generally healthy adults with a recent colorectal adenoma; 72% men
Intervention: Calcium carbonate providing 1,200 mg calcium daily or placebo
Outcome: All fractures and minimal-trauma fractures during and after treatment

Funding or conflict note: No conflicts were declared, and the PubMed record states sponsors did not participate in design, conduct, analysis, interpretation, or manuscript decisions.

Open research record ↗

2006

Mixed or qualifiedPMID 16636212

Effects of calcium supplementation on clinical fracture and bone structure in elderly women

Intention-to-treat fracture risk was not significantly lower (HR 0.87, 95% CI 0.67–1.12), although bone measures improved and an adherent subgroup had fewer fractures. Constipation increased from 9.1% to 13.4%; subgroup adherence findings do not replace the randomized primary result.

Published: 2006Duration: 5 yearsn=1,460 participants

Study design and methods

Design: Randomized, double-blind, placebo-controlled trial
Population: 1,460 community-dwelling women older than 70; mean age 75
Intervention: Calcium carbonate providing 1,200 mg calcium daily or placebo
Outcome: Clinical osteoporotic fractures, vertebral deformity, bone measures, and adverse events

Open research record ↗

Unscreened discovery appendix—not evidence253 candidate publicationsSearch run: Aug 21, 2026

Complete for the displayed PubMed query at the search timestamp—not for all databases or every possible synonym. Candidates can be irrelevant, duplicate the same study, or report negative findings. They are never summed as evidence or participants until screened.

03 / SOURCES

Start with the source material

Official evidence overviewPubMed bounded human-evidence search Live PubMed discovery searchNational Library of Medicine

The live search is for discovery only. Search-result counts change and are not included in the audited totals above.

Recent PubMed discovery recordsDirect links to the first 12 records returned by the reproducible search. These are discovery candidates—not reviewed summaries or a count of supportive findings.

04 / EXPERT CONTEXT

Expert context—not evidence

Expert positions are dated context—not scientific evidence. They never raise the evidence status or become consensus by repetition.

No direct, source-verified endorsement is currently recorded. Research authorship or discussion alone is not treated as endorsement.