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Study of Vitamin D and Omega-3 Supplementation for Preventing Diabetes

NCT01633177 · Status: COMPLETED · Phase: PHASE3 · Type: INTERVENTIONAL · Enrollment: 22220

Last updated 2026-04-03

Study results available
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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 ancillary study (n=22220 without diabetes at baseline) 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.

Conditions

Interventions

DIETARY_SUPPLEMENT

Vitamin D3

Vitamin D3 (cholecalciferol), 2000 IU per day.

DRUG

Omega-3 fatty acid (fish oil)

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 \[DHA\]).

DIETARY_SUPPLEMENT

Vitamin D3 placebo

Vitamin D3 placebo

DRUG

Fish oil placebo

Fish oil placebo

Sponsors & Collaborators

  • National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

    collaborator NIH

  • Brigham and Women's Hospital

    lead OTHER

Principal Investigators

  • Aruna Pradhan, MD, MPH · Brigham and Women's Hospital

Study Design

Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Model
FACTORIAL

Eligibility

Min Age
50 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2011-11-30
Primary Completion
2024-05-30
Completion
2024-05-30
FDA Drug
Yes

Countries

  • United States

Study Locations

More Related Trials

Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT01633177 on ClinicalTrials.gov