CI

At a glance

ClinicalIndex Comparison Record
Phase 3Completed· 22,220 enrolled
Drug / intervention
Omega-3 fatty acid (fish oil) +3 moredrug
Likely dose
Omega-3 fatty acid (fish oil) 840 milligramsfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT01633177
NCT01633177Phase 3Completed

Diabetes Prevention in the Vitamin D and Omega-3 Trial

Brigham and Women's Hospital·interventional·Posted Jul 4, 2012·Updated Apr 3, 2026

In Brief

A Phase 3 clinical trial evaluating Vitamin D3, Omega-3 fatty acid (fish oil), and 2 other interventions for Type 2 Diabetes. Completed, enrolled 22,220 participants across 1 site.

Detailed 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.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
ConditionsType 2 Diabetes
CountriesUnited States

Timeline

Phase 3CompletedFinished
201220132014201520162017201820192020202120222023202420252026
First PostedJul 4, 2012
Enrollment StartNov 1, 2011
Primary CompletionMay 30, 2024
TodayJul 2, 2026
Enrollment to primary: 12.6 yearsPosted 14.0 years ago

Interventions

Vitamin D3dietary

Vitamin D3 (cholecalciferol), 2000 IU per day.

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 \[DHA\]).

Vitamin D3 placebodietary

Vitamin D3 placebo

Fish oil placebodrug

Fish oil placebo