Meta-analysis of Randomized Controlled Trials on Vitamins and Mineral Supplementation for CVD Prevention and Treatment

February 22, 2018 updated by: David Jenkins, University of Toronto

Supplemental Vitamins and Minerals for CVD Prevention and Treatment: Systematic Review and Meta-analyses of the Data (Meta-analyses and RCTs) Published Since 2012

The use of vitamin and mineral supplementation has historically been to treat and prevent micronutrient deficiencies. In recent years, however, and with their widespread use, the interest has shifted toward a possible role in the prevention and treatment of chronic diseases. The investigators will review and perform meta-analyses of vitamin and mineral supplementation trials in relation to cardiovascular disease. Publications from 2012, both before and including the US Preventive Service Task Force (USPSTF) 2014 review, will be included in the review.

Study Overview

Status

Unknown

Detailed Description

Search strategy:

A literature search of the Cochrane Library, Medline and PubMed will be conducted with the following search terms: "dietary supplements or supplement*" AND "cardiovascular disease or myocardial infarction or stroke or cardiovascular death or mortality or all-cause mortality or death." Specific searches will be conducted for individual supplements and included multivitamins, antioxidants, vitamin A, β-carotene, B1, B2, B3 (niacin), B6, B10 (folic acid), B-complex, C, D and E, calcium, iron, zinc, magnesium and selenium. The search will be limited to meta-analyses and RCTs.

Analysis:

Full article review and data extraction will be conducted by two independent investigators, with all disparities reconciled through consensus. The extracted data will include number of cases and total participants/population for the intervention and control group.

Data will be analyzed using Review Manager (RevMan) version 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark) and publication bias will be conducted using STATA software, version 13.0 (College Station, TX, USA). Heterogeneity will be assessed using the Cochran Q statistic at p<0.1 and quantified by the I² statistic. Publication bias will be investigated by visual inspection of funnel plots and quantitative assessment using Begg's and Egger's tests where p<0.05 is considered evidence of small study effects. If <10 trials are available in a meta-analysis, publication bias analysis will not be assessed due to insufficient power.

Risk of bias The Cochrane risk of bias tool which is based on randomization, allocation concealment, blinding, completeness of follow-up and intention-to-treat will be used to assess eligible RCTs.

Grading of the evidence The quality and strength of the evidence will be assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. Using the GRADE tool, evidence will be graded as high, moderate, low, or very low quality evidence using the following criteria: study limitations (as assessed by the Cochrane Risk of Bias Tool), inconsistency (substantial) unexplained inter-study heterogeneity, I2>50% and p<0.1; indirectness (presence of factors that limit the generalizability of the results); imprecision (the 95% CI for effect estimates crosses a minimally important difference (MID) of 5% [RR 0.95-1.05]) from the line of unity; and publication bias (significant evidence of small-study effects).

Study Type

Observational

Enrollment (Anticipated)

1

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Adults free of serious chronic disease infections.

Description

Inclusion Criteria:

  • English studies
  • Supplements taken orally for at least 6 months

Exclusion Criteria:

  • Studies in children
  • Studies in women who are pregnant or breastfeeding
  • Studies of adults who have serious chronic disease infections such as HIV
  • Studies with combined interventions and no adequate control group (i.e. interventions other than the supplement must be provided to the control group as well)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Supplementation
supplementation with a vitamin or mineral: vitamin A, β-carotene, B1, B2, B3 (niacin), B6, B10 (folic acid), C, D and E, calcium, iron, zinc, magnesium and selenium. Also, multivitamins, antioxidants, B-complex and the combination of calcium and vitamin D.
No Supplementation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
All-cause mortality
Time Frame: 1 year
1 year
Myocardial infarction (MI)
Time Frame: 1 year
1 year
Stroke
Time Frame: 1 year
1 year
Cardiovascular disease (CVD)
Time Frame: 1 year
1 year
Coronary heart disease (CHD)
Time Frame: 1 year
1 year
CVD mortality
Time Frame: 1 year
1 year
CHD mortality
Time Frame: 1 year
1 year
MI mortality
Time Frame: 1 year
1 year
stroke mortality
Time Frame: 1 year
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

July 1, 2016

Primary Completion (ANTICIPATED)

April 1, 2018

Study Completion (ANTICIPATED)

June 1, 2018

Study Registration Dates

First Submitted

February 16, 2018

First Submitted That Met QC Criteria

February 16, 2018

First Posted (ACTUAL)

February 22, 2018

Study Record Updates

Last Update Posted (ACTUAL)

February 26, 2018

Last Update Submitted That Met QC Criteria

February 22, 2018

Last Verified

February 1, 2018

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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