Two Randomized Trials of Low-Dose Calcium Supplementation in Pregnancy.

Name: Αlpha¹ Rigor Record — Two Randomized Trials of Low-Dose Calcium Supplementation in Pregnancy.
Item: Two Randomized Trials of Low-Dose Calcium Supplementation in Pregnancy.
Rating: 39
Author: Αlpha¹

Dwarkanath P, Muhihi A, Sudfeld CR, Wylie BJ, Wang M, Perumal N, Thomas T, Kinyogoli SM, Bakari M, Fernandez R, Raj JM, Swai NO, Buggi N, Shobha R, Sando MM, Duggan CP, Masanja HM, Kurpad AV, Pembe AB, Fawzi WW

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Αlpha¹ Rigor Review — 1★ (Critical), 1 critical, 3 high issues for “Two Randomized Trials of Low-Dose Calcium Supplementation in Pregnancy.”

Links back to this Rigor Record.

Αlpha¹ Editorial

This rigor review was examined and confirmed by Αlpha¹ Editorial · August 16, 2026

Αlpha¹ Rigor Review

Rigor Reviewed

1 / 5

Critical — a demonstrable failure

Interventional Study

Critical

High-priority

How this rating was calculated▸

Started at 5★ — deductions

StatisticsImpossible or misreported statistic−1★
StatisticsPrinted percentage does not match its own count (capped)−0.25★
ReportingData & code availability partially met−0.25★

A demonstrable critical failure caps the rating at the minimum, regardless of the deductions above.

Model-reported confidence: moderateReviewer agreement: highEngine: 7.39.0Source: full text

Problems surfaced3 types

Numerical inconsistencies1

Values that contradict each other or are impossible for the stated sample: recomputed p-values and test statistics, GRIM/GRIMMER checks on summary numbers, percentages against their own counts, totals against their parts, and estimates against their own confidence intervals.

Printed percentage does not match its own countRecomputed

Overstated conclusions1

Conclusions that reach past what the paper's own results support — including a significance claim that no longer holds when the statistic is recomputed, and efficacy resting on an unvalidated surrogate endpoint.

Significance claim flips when recomputedRecomputed

Reporting gaps1

Required detail the manuscript never states — study design, biological variables, ethics approval and consent, key resources, statistical reporting, data and code availability, and overall transparency.

Data/code availability incompleteAssessed

This Αlpha¹ Rigor Review uses AI Rigor Reviewers trained on a curated corpus of high-fidelity and retracted papers, with expert supervision and curation. It can still make mistakes; verify each finding against the source before relying on it.

Critical findings

• Recomputed 2 tests: 1 consistent, 1 inconsistent (1 change significance at p<.05); 2 via agent-written checks. 1 printed percentage that does not match its own count.

The paper reports two well-designed randomized noninferiority trials with strong methodology, clear reporting, and appropriate ethical approvals. The main weaknesses are a vague data sharing statement and a potential statistical inconsistency in a key noninferiority p-value that warrants verification.

Both reviewers agreed on study type (interventional) and on most dimensions. The statistical analysis dimension was downgraded from pass to warn based on the deterministic statistics check, which found one inconsistent p-value. The data code availability warning is based on the vague data sharing statement.

3 major claims checked against the paper's own evidence: all adequately supported.

Efficacy claim is anchored to an adequate endpoint and a meaningful effect.

Recomputed 2 tests: 1 consistent, 1 inconsistent (1 change significance at p<.05); 2 via agent-written checks. 1 printed percentage that does not match its own count.

Reporting

Eight Dimensions7 pass · 1 warn

The introduction cites WHO recommendations and placebo-controlled trials showing high-dose calcium reduces preeclampsia and preterm birth, and notes implementation barriers. It acknowledges limitations of prior low-dose trials (small sample sizes) and states the hypothesis that low-dose may be as efficacious as high-dose. The rationale links the premise to the study objectives.

Sub-criteria

prior work citedADEQUATE

premise rationaleADEQUATE

limitations addressedADEQUATE

Per reviewer (2) — the votes behind the verdict

PASSReviewer 1· 95% conf

The paper establishes a clear scientific premise based on WHO recommendations and prior trials, with a logical rationale for the hypothesis.

Evidence

direct quote[Introduction, paragraph 2]

“Calcium supplementation in pregnancy has been recommended by the World Health Organization (WHO) since 2011 to reduce the risk of preeclampsia in populations with low dietary calcium intake.”