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Completed Phase 2Phase 3 Interventional Results available

Vitamin D/Calcium Polyp Prevention Study

ClinicalTrials.gov ID: NCT00153816

Public ClinicalTrials.gov record NCT00153816. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 11, 2026, 7:44 PM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

Extensive experimental and observational data suggest that intake of calcium and of vitamin D exert protective effects on colorectal neoplasia. Building on their previous work, the investigators will investigate the chemopreventive effect of vitamin D in the large bowel, to study whether calcium with vitamin D is more effective than calcium alone, and to confirm their positive finding regarding calcium. The goal of this study is the development of chemopreventive combinations that will reduce risk of colorectal neoplasia sufficiently to permit the lengthening of surveillance intervals in most patients and to clarify important issues regarding the mechanisms of colorectal carcinogenesis and chemoprevention.

Study identification

NCT ID
NCT00153816
Recruitment status
Completed
Study type
Interventional
Phase
Phase 2, Phase 3
Enrollment
2,813 participants

Conditions and interventions

Eligibility (public fields only)

Age range
45 Years to 75 Years
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Jun 30, 2004
Primary completion
Sep 30, 2013
Completion
May 31, 2016
Last update posted
Mar 14, 2017

2004 – 2016

United States locations

U.S. sites
10
U.S. states
10
U.S. cities
10
Facility City State ZIP Site status
University of Southern California Los Angeles California 90089
University of Colorado Denver Colorado 80220
Emory University Atlanta Georgia 30322
University of Iowa Iowa City Iowa 52242
University of Minnesota Minneapolis Minnesota 55455
Dartmouth Hitchcock Medical Center Lebanon New Hampshire 03766
University of North Carolina Chapel Hill North Carolina 27599
Cleveland Clinic Foundation Cleveland Ohio 44195
University of South Carolina Columbia South Carolina 29203
University of Texas Houston Texas 77030

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

Non-U.S. locations

This page focuses on the U.S. directory. The official record also lists 1 non-U.S. site.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT00153816, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Mar 14, 2017 · Synced Sep 11, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT00153816 live on ClinicalTrials.gov.

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