Calcium (carbonate vs citrate) and heart
What 4 graded rows on calcium (carbonate vs citrate) agree on for heart, and where they differ. Counted side by side, never averaged.
Consensus finder Rows from the Calcium (carbonate vs citrate) page, reviewed Oct 21, 2026 How it decides
What the rows agree on
Each block and row is one graded row from the Calcium (carbonate vs citrate) page, with its PubMed record.
Your question
Calcium (carbonate vs citrate) and heart
4 rows · 69,833 peopleSplit. 1 row found an improvement, 1 found no difference and 2 found a worse outcome.
- AGrade A× 1
- CGrade C× 2
- ∅No effect× 1
- Rows
- 4
- Trials
- 4
- At least: a review without a trial count
- People
- 69,833
- Pooled reviews may count some twice
Where they differ
From the rowsThe best-graded row, grade A, is a systematic review of 3,140 people (2022) and found an improvement. 1 row is graded No effect, our grade for adequately powered trials that found no effect.
The 2 rows that found a worse outcome were larger: a median of 25,665 people, against 3,140 people for the row that found an improvement.
Only the 2 rows that found a worse outcome name women in their population.
The row that found an improvement is newer (2022) than the 2 rows that found a worse outcome (2010 to 2021).
The best grade is A among the row that found an improvement, and C among the rows that found a worse outcome.
The rows
1 improved · 1 no difference · 2 worse- CGrade CCardiovascular disease events (double-blind placebo-controlled trials) · Worse
Meta-analysis · n 43,178 · 2021 · Participants in 13 double-blind, placebo-controlled trials; the signal was seen in healthy postmenopausal women
Subgroup signal at 1,000 mg/day supplemental calcium · Varied across trials
Cardiovascular disease risk was 15% higher (RR 1.15; 95% CI 1.06 to 1.25) and coronary heart disease 16% higher (RR 1.16; 95% CI 1.05 to 1.28) with calcium supplements.
Row on the Calcium (carbonate vs citrate) page · PubMed 33530332 (opens PubMed)
- CGrade CHeart and blood-vessel events with calcium alone · Worse
Meta-analysis · n 8,151 · 2010 · Adults with mean age over 40 in placebo-controlled trials lasting over a year (patient-level data from 5 trials)
500 mg/day or more · Median follow-up 3.6 years
Myocardial infarction was more common with calcium (HR 1.31; 95% CI 1.02 to 1.67); stroke, the composite end point and death were not significantly increased. Trial-level data (n=11 921) showed a similar result (RR 1.27).
Row on the Calcium (carbonate vs citrate) page · PubMed 20671013 (opens PubMed)
- AGrade ABlood pressure in people with normal blood pressure · Improved
Systematic review · n 3,140 · 2022 · Normotensive people in 18 randomized trials (Cochrane review update)
Below 1,000 to above 1,500 mg/day; systolic effect significant at 1,000–1,500 mg/day · Varied across trials
Systolic blood pressure fell by 1.37 mmHg (95% CI -2.08 to -0.66) and diastolic by 1.45 mmHg (95% CI -2.23 to -0.67), high-certainty evidence. Effects were larger in people younger than 35 (systolic -1.86, diastolic -2.50 mmHg).
Row on the Calcium (carbonate vs citrate) page · PubMed 35014026 (opens PubMed)
- ∅No effectPre-eclampsia with calcium during pregnancy · No difference
Systematic review · n 15,364 · 2025 · Pregnant women in 6 placebo-controlled trials (Cochrane review; trials after 2010 had to be prospectively registered, and trustworthiness was assessed)
Doses varied across trials; low vs high dose compared in 2 further trials (22,000 women) · During pregnancy
Little to no difference in pre-eclampsia (RR 0.83; 95% CI 0.67 to 1.04; low certainty); limited to large trials, RR 0.92 (0.79 to 1.05; high certainty). Low- and high-dose calcium did not differ (RR 0.96; 95% CI 0.73 to 1.25).
Row on the Calcium (carbonate vs citrate) page · PubMed 41330480 (opens PubMed)