NCT01633177

Brief Summary

The VITamin D and OmegA-3 TriaL (VITAL; NCT 01169259) is an ongoing randomized clinical trial in 25,875 U.S. men and women investigating whether taking daily dietary supplements of vitamin D3 (2000 IU) or omega-3 fatty acids (Omacor® fish oil, 1 gram) reduces the risk of developing cancer, heart disease, and stroke in people who do not have a prior history of these illnesses. This ancillary study is being conducted among nondiabetic participants in VITAL and will examine whether vitamin D or fish oil prevent type 2 diabetes. Findings from this proposed study conducted within the VITAL trial will clarify whether vitamin D and omega-3 fatty acid supplementation reduces risk of type 2 diabetes and thus will inform public health and clinical guidelines for diabetes prevention.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
25,875

participants targeted

Target at P75+ for not_applicable type-2-diabetes

Timeline
Completed

Started Sep 2010

Longer than P75 for not_applicable type-2-diabetes

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

September 1, 2010

Completed
1.8 years until next milestone

First Submitted

Initial submission to the registry

June 26, 2012

Completed
8 days until next milestone

First Posted

Study publicly available on registry

July 4, 2012

Completed
11.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 30, 2024

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

May 30, 2024

Completed
Last Updated

May 31, 2023

Status Verified

May 1, 2023

Enrollment Period

13.8 years

First QC Date

June 26, 2012

Last Update Submit

May 30, 2023

Conditions

Type 2 Diabetes

Keywords

vitamin Domega-3 fatty acidsType 2 diabetesOral glucose tolerance test (OGTT)Insulin sensitivityBeta-cell function

Outcome Measures

Primary Outcomes (1)

  • Incident type 2 diabetes

    5 years

Secondary Outcomes (3)

  • OGTT index of insulin sensitivity

    2 years

  • OGTT index of beta-cell function

    2 years

  • HbA1c levels

    2 years

Study Arms (4)

Vitamin D and Omega-3

ACTIVE COMPARATOR
Dietary Supplement: Vitamin D3Drug: Omega-3 fatty acid (fish oil)

Vitamin D and Omega-3 placebo

ACTIVE COMPARATOR
Dietary Supplement: Vitamin D3Drug: Fish oil placebo

Vitamin D placebo and Omega-3

ACTIVE COMPARATOR
Drug: Omega-3 fatty acid (fish oil)Dietary Supplement: Vitamin D3 placebo

Vitamin D placebo and Omega-3 placebo

PLACEBO COMPARATOR
Dietary Supplement: Vitamin D3 placeboDrug: Fish oil placebo

Interventions

Vitamin D3DIETARY_SUPPLEMENT

Vitamin D3 (cholecalciferol), 2000 IU per day.

Also known as: cholecalciferol
Vitamin D and Omega-3Vitamin D and Omega-3 placebo
Omega-3 fatty acid (fish oil)DRUG

Omacor, 1 capsule per day. Each capsule of Omacor contains 840 milligrams of marine omega-3 fatty acids (465 mg of eicosapentaenoic acid \[EPA\] and 375 mg of docosahexaenoic acid \[DHA\]).

Also known as: fish oil, eicosapentaenoic acid, docosahexaenoic acid, EPA, DHA, Omacor®
Vitamin D and Omega-3Vitamin D placebo and Omega-3
Vitamin D3 placeboDIETARY_SUPPLEMENT

Vitamin D3 placebo

Vitamin D placebo and Omega-3Vitamin D placebo and Omega-3 placebo
Fish oil placeboDRUG

Fish oil placebo

Vitamin D and Omega-3 placeboVitamin D placebo and Omega-3 placebo

Eligibility Criteria

Age50 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)
Participants in VITAL (NCT01169259) who have no history of diabetes mellitus at baseline are eligible to participate in this ancillary study.

Contact the study team to discuss eligibility requirements. They can help determine if this study is right for you.

Sponsors & Collaborators

Study Sites (1)

Division of Preventive Medicine, Brigham and Women's Hospital

Boston, Massachusetts, 02215, United States

Location

Related Publications (1)

  • Tobias DK, Pradhan AD, Duran EK, Li C, Song Y, Buring JE, Cook NR, Mora S, Manson JE. Vitamin D supplementation vs. placebo and incident type 2 diabetes in an ancillary study of the randomized Vitamin D and Omega-3 Trial. Nat Commun. 2025 Apr 8;16(1):3332. doi: 10.1038/s41467-025-58721-6.

    PMID: 40199888DERIVED

MeSH Terms

Conditions

Diabetes Mellitus, Type 2Insulin Resistance

Interventions

CholecalciferolFatty Acids, Omega-3Fish OilsEicosapentaenoic AcidDocosahexaenoic AcidsOmacor

Condition Hierarchy (Ancestors)

Diabetes MellitusGlucose Metabolism DisordersMetabolic DiseasesNutritional and Metabolic DiseasesEndocrine System DiseasesHyperinsulinism

Intervention Hierarchy (Ancestors)

CholestenesCholestanesSteroidsFused-Ring CompoundsPolycyclic CompoundsSterolsVitamin DSecosteroidsMembrane LipidsLipidsDietary Fats, UnsaturatedDietary FatsFatsFatty Acids, UnsaturatedFatty AcidsOilsEicosanoids

Study Officials

  • Yiqing Song, MD, ScD

    Brigham and Women's Hospital

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
PREVENTION
Intervention Model
FACTORIAL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Principal Investigator

Study Record Dates

First Submitted

June 26, 2012

First Posted

July 4, 2012

Study Start

September 1, 2010

Primary Completion

May 30, 2024

Study Completion

May 30, 2024

Last Updated

May 31, 2023

Record last verified: 2023-05

Locations

US(1)