Evidence map›Paper›PMID 22492364›Full record

SynthesisThe American journal of clinical nutrition2012

Effects of vitamin C supplementation on blood pressure: a meta-analysis of randomized controlled trials.

Stephen P Juraschek, Eliseo Guallar, Lawrence J Appel, Edgar R Miller

Registry-linked trialAbstract readMeta-AnalysisSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in The American journal of clinical nutrition, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06995586 (The Synergistic Action of Vitamins and Dietary Supplements in Patients With Coronary Artery Bypass Grafting for Improving the Quality of Healthcare Delivery.), which is not on this map. Cited by 129 papers, 17 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
129citing papers in PubMed, 17 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT06995586 nanot yet recruitingnot on this mapstarted 2026, after this paper: background citation

The Synergistic Action of Vitamins and Dietary Supplements in Patients With Coronary Artery Bypass Grafting for Improving the Quality of Healthcare Delivery.

TypeinterventionalSponsorNicosia General HospitalRan2026 to 2028Enrolled108ConditionsCardio-pulmonary Bypass, Cardiovascular Diseases, Omega-3 Polyunsaturated Fatty Acids, Omega-3 SupplementationArmsVitamin C, Omega 3 PUFA (EPO/DHA), Lignin, Lactulose
3 · Its place in the literature

Who cites it

129 citing papers in PubMed, 17 syntheses or guidelines pooled it.

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  3. Effect of vitamin BBMJ open · 2024
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  15. Fruit and Vegetables Consumption and Risk of Hypertension: A Meta-Analysis.Journal of clinical hypertension (Greenwich, Conn.) · 2016
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69 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

4 authors.

Stephen P JuraschekJohns Hopkins School of Medicine, Johns Hopkins Bloomberg School of Public Health, and Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD 21205, USA.
Eliseo Guallar
Lawrence J Appel
Edgar R Miller

Funding

CARDIOVASCULAR EPIDEMIOLOGY INSTITUTIONAL TRAININGT32HL007024 · NHLBI · JOHNS HOPKINS UNIVERSITY · PI Elizabeth Selvin · 1985 to 2026
$17.5M
NHLBI NIH HHS T32HL007024
6 · The paper itself

Abstract

backgroundIn observational studies, increased vitamin C intake, vitamin C supplementation, and higher blood concentrations of vitamin C are associated with lower blood pressure (BP). However, evidence for blood pressure-lowering effects of vitamin C in clinical trials is inconsistent.

objectiveThe objective was to conduct a systematic review and meta-analysis of clinical trials that examined the effects of vitamin C supplementation on BP.

designWe searched Medline, EMBASE, and Central databases from 1966 to 2011. Prespecified inclusion criteria were as follows: 1) use of a randomized controlled trial design; 2) trial reported effects on systolic BP (SBP) or diastolic BP (DBP) or both; 3) trial used oral vitamin C and concurrent control groups; and 4) trial had a minimum duration of 2 wk. BP effects were pooled by random-effects models, with trials weighted by inverse variance.

resultsTwenty-nine trials met eligibility criteria for the primary analysis. The median dose was 500 mg/d, the median duration was 8 wk, and trial sizes ranged from 10 to 120 participants. The pooled changes in SBP and DBP were -3.84 mm Hg (95% CI: -5.29, -2.38 mm Hg; P < 0.01) and -1.48 mm Hg (95% CI: -2.86, -0.10 mm Hg; P = 0.04), respectively. In trials in hypertensive participants, corresponding reductions in SBP and DBP were -4.85 mm Hg (P < 0.01) and -1.67 mm Hg (P = 0.17). After the inclusion of 9 trials with imputed BP effects, BP effects were attenuated but remained significant.

conclusionsIn short-term trials, vitamin C supplementation reduced SBP and DBP. Long-term trials on the effects of vitamin C supplementation on BP and clinical events are needed.

Indexed as

Dietary SupplementsAscorbic AcidBlood PressureHumansHypertensionRandomized Controlled Trials as TopicVitaminsAscorbic AcidVitamins

Identifiers

PMID22492364
PMCPMC3325833

What OpenQuestion holds

Textmetadata
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Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.