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Completed Phase 2 Interventional Accepts healthy volunteers

Vitamin D, Glucose Control and Insulin Sensitivity in African-Americans

ClinicalTrials.gov ID: NCT00784511

Public ClinicalTrials.gov record NCT00784511. 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 10, 2026, 3:27 AM 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.

North American blacks tend to have low blood levels of vitamin D because pigmentation blocks vitamin D production in the skin. They also have higher rates of developing type 2 diabetes and higher rates of complications from the disease compared with whites. Although there is compelling evidence that adequate vitamin D may reduce the risk for type 2 diabetes in whites, recent evidence from a national survey demonstrated an association of vitamin D with diabetes in whites but not in blacks. However, the central hypothesis of this study is that providing enough supplemental vitamin D to blacks (raising their blood levels higher than that of most participants in the survey) will improve blood measures related to diabetes risk. The proposed study is a 12-week randomized, double-blind, placebo-controlled experiment designed to examine the effect of vitamin D supplementation (100 μg/d ) on insulin secretion, insulin sensitivity and glucose control in pre-diabetic black men and women aged 40 and older.

Study identification

NCT ID
NCT00784511
Recruitment status
Completed
Study type
Interventional
Phase
Phase 2
Lead sponsor
Tufts University
Other
Enrollment
100 participants

Conditions and interventions

Interventions

Dietary Supplement · Other

Eligibility (public fields only)

Age range
40 Years and older
Sex
All
Healthy volunteers
Accepts healthy volunteers

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

Study timeline

Start date
Jun 30, 2008
Primary completion
Jan 31, 2011
Completion
Jan 31, 2011
Last update posted
Nov 13, 2014

2008 – 2011

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University Boston Massachusetts 02111

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

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT00784511, 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 Nov 13, 2014 · Synced Sep 10, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT00784511 live on ClinicalTrials.gov.

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