Calcium citrate: molecular mechanisms & dependencies

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

Human evidence only

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

Where it participates (unsigned role)

An older-women calcium trial showed an upward myocardial-infarction signal that weakened when registry events were added.
Calcium → Myocardial infarction incidence source_derived_draftungraded
Experimental context and source evidence
experimental_model
1471 postmenopausal women, five-year randomized trial; secondary cardiovascular analysis.
exposure
Calcium citrate tablets versus placebo in the parent randomized trial; calcium-only intervention, not the WHI calcium-plus-vitamin-D regimen.
limitations
Adjudicated reported MI RR 2.12 (1.01-4.47); including unreported registry events RR 1.49 (0.86-2.57). Does not establish vascular calcification as the mediator.
nutrient_topic
Calcium research collection; topical membership is not evidence of a direct dietary effect. · Calcium
organism
Homo sapiens
plain_language
The heart-event result depended partly on how events were collected.
primary_references
[cal-clin-bolland2008] Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial (2008). https://pubmed.ncbi.nlm.nih.gov/18198394/ DOI: 10.1136/bmj.39440.525752.BE
tissue_or_cell_type
Human clinical or absorption endpoint
Calcium: mechanism-first literature curation (2026-09-17) · lines 1281–1291
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · 1471 postmenopausal women, five-year randomized trial; secondary cardiovascular analysis. · source_derived_draft · unverified_draft
### cal-bolland-myocardial-events An older-women calcium trial showed an upward myocardial-infarction signal that weakened when registry events were added. Condition category: normal nutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect. plain_language: The heart-event result depended partly on how events were collected. organism: Homo sapiens tissue_or_cell_type: Human clinical or absorption endpoint experimental_model: 1471 postmenopausal women, five-year randomized trial; secondary cardiovascular analysis. limitations: Adjudicated reported MI RR 2.12 (1.01-4.47); including unreported registry events RR 1.49 (0.86-2.57). Does not establish vascular calcification as the mediator. exposure: Calcium citrate tablets versus placebo in the parent randomized trial; calcium-only intervention, not the WHI calcium-plus-vitamin-D regimen. [cal-clin-bolland2008] Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial (2008). https://pubmed.ncbi.nlm.nih.gov/18198394/ DOI: 10.1136/bmj.39440.525752.BE
Complete structured claim and evidence
Fasting achlorhydric participants absorbed substantially less calcium from carbonate than from citrate.
Calcium carbonate → Intestinal calcium absorption source_derived_draftungraded
Experimental context and source evidence
experimental_model
11 achlorhydric patients and nine controls; 250 mg calcium isotope tests.
exposure
Fasting achlorhydric mean fractions: carbonate 0.042, citrate 0.452; normal subjects showed no significant formulation difference.
limitations
Not evidence that carbonate always fails or citrate always outperforms it.
nutrient_topic
Calcium research collection; topical membership is not evidence of a direct dietary effect. · Calcium
organism
Homo sapiens
plain_language
Low stomach acid can change how a calcium preparation is absorbed.
primary_references
[cal-clin-recker1985] Calcium absorption and achlorhydria (1985). https://pubmed.ncbi.nlm.nih.gov/4000241/ DOI: 10.1056/NEJM198507113130202
tissue_or_cell_type
Human clinical or absorption endpoint
Calcium: mechanism-first literature curation (2026-09-17) · lines 1164–1174
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · 11 achlorhydric patients and nine controls; 250 mg calcium isotope tests. · source_derived_draft · unverified_draft
### cal-carbonate-fasting-achlorhydria Fasting achlorhydric participants absorbed substantially less calcium from carbonate than from citrate. Condition category: normal nutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect. plain_language: Low stomach acid can change how a calcium preparation is absorbed. organism: Homo sapiens tissue_or_cell_type: Human clinical or absorption endpoint experimental_model: 11 achlorhydric patients and nine controls; 250 mg calcium isotope tests. limitations: Not evidence that carbonate always fails or citrate always outperforms it. exposure: Fasting achlorhydric mean fractions: carbonate 0.042, citrate 0.452; normal subjects showed no significant formulation difference. [cal-clin-recker1985] Calcium absorption and achlorhydria (1985). https://pubmed.ncbi.nlm.nih.gov/4000241/ DOI: 10.1056/NEJM198507113130202
Complete structured claim and evidence

The events it takes part in

A mechanism often involves more than two components. These are the full events, with every participant and its role.

Situations it appears in

Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

Open hypotheses

Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.

This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

Calcium citrate