Massive study tests if daily pills can ward off cancer and heart attacks

NCT ID NCT01169259

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing This study
Running, but no longer taking on new participants.
Completed
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Jun 25, 2026 · Last updated Jul 31, 2026 · Updated 3 times

Summary

This large study tested whether taking daily vitamin D3 and omega-3 (fish oil) supplements can lower the risk of developing cancer, heart disease, or stroke. Over 25,000 healthy older adults (men 50+, women 55+) took the supplements or placebos for about 5 years. The goal is to see if these common supplements can prevent serious illnesses in people without a prior history.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
vitamin D3 (cholecalciferol) and omega-3 fatty acids (fish oil)
What this could lead to
If it works, this could show that simple daily supplements help prevent cancer and heart disease in healthy older adults.
What could go wrong
This is a large, completed phase 3 trial, but results may show no benefit or only modest effects. Supplements are not a substitute for other healthy habits.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Phase 3

Large-scale testing in a bigger group. Usually the last step before a treatment can be approved.

Participants

25,871 people

The number who actually took part.

Started

Jul 2010

Expected to finish

Oct 2026

An estimate. End dates often move.

Lead sponsor

Other sponsor

The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

50 years and older

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

To be eligible for the study, respondents had to, at study entry,: 1. be men aged 50 or older or women aged 55 or older; 2. have no history of cancer (except non-melanoma skin cancer), heart attack, stroke, transient ischemic attack, angina pectoris, coronary-artery bypass grafting, or percutaneous coronary intervention; 3. have none of the following safety exclusions: history of renal failure or dialysis, hypercalcemia, hypo- or hyperparathyroidism, severe liver disease (cirrhosis), or sarcoidosis or other granulomatous diseases such as active chronic tuberculosis or granulomatosis with polyangiitis (Wegener's); 4. have no allergy to fish or soy; 5. have no other serious illness that would preclude participation; 6. be consuming no more than 800 IU of vitamin D from all supplemental sources combined (individual vitamin D supplements, calcium+vitamin D supplements, medications with vitamin D \[e.g., Fosamax Plus D\], and multivitamins), or, if taking, willing to decrease or forego such use during the trial; 7. be consuming no more than 1200 mg/d of calcium from all supplemental sources combined, or, if taking, willing to decrease or forego such use during the trial; 8. not be taking fish oil supplements, or, if taking, willing to forego their use during the trial

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Brigham and Women's Hospital

    Boston, Massachusetts, 02215, United States

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