The Effect of Vitamin D Supplementation on Glucose Metabolism in Non-Diabetic African American Adults

Not Applicable

Completed

• Conditions: Type 2 Diabetes
• Interventions: Dietary Supplement: Inactive comparator; Dietary Supplement: vitamin D3, cholecalciferol

• Registration Number: NCT01141192
• Lead Sponsor: Augusta University

Brief Summary

Type 2 diabetes is more common among African Americans than Caucasians. African Americans are also at a higher risk for lower levels of vitamin D compared to other ethnic groups. The investigators don't yet know if there is a connection between not having enough vitamin D and type 2 diabetes in African Americans. Researchers have found that the less vitamin D Caucasians had the higher the chance they would have type 2 diabetes but it is less clear if this is the case for African Americans. The investigators want to better understand how vitamin D status and diabetes risk are linked in African Americans. Also, the investigators want to see if supplementation with vitamin D will improve your blood pressure, blood sugar, \& insulin. All of these are in some way related to diabetes. The investigators want to measure changes in blood sugar \& blood pressure in people who do not have diabetes with the hope of learning new information to help treat those that do have diabetes.

The investigators hypothesize that vitamin D status is related to diabetes risk measured by hemoglobin A1c (a test of glucose level over time), fasting glucose and insulin in non-diabetic African American adults and that body weight status may affect vitamin D status in response to vitamin D supplements compared to placebo.

Detailed Description

Participants will be randomly assigned to receive either a 60,000 IU vitamin D3 supplement every four weeks or an inactive placebo. All investigators and the participants will be blinded to the assignment group of each participant until all testing is completed.

Study Timeline

• Study Start: 2010-01
• Primary Completion: 2010-05
• Study Completion: 2010-05
• Status Verified: 2010-06
• Study First Submitted: 2010-06-04
• Study First Submitted QC: 2010-06-09
• Last Update Submitted: 2010-06-09
• Study First Posted: 2010-06-10
• Last Update Posted: 2010-06-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 48

Inclusion Criteria

• African American by self-report
• In good health

Exclusion Criteria

• Diagnosis of diabetes
• Health problems/medication affecting calcium and/or vitamin D metabolism
• Current use of vitamin/mineral/herbal/nutritional supplements
• Inability to swallow pills
• Pregnancy

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Sugar Pill	Inactive comparator	Inactive placebo tablets identical in appearance to the active comparator provided every four weeks at weeks 0,4,8,and 12.
Vitamin D3 supplement	vitamin D3, cholecalciferol	60,000 IU vitamin D3 oral supplement provided every four weeks at weeks 0, 4, 8, and 12 in the form of one 50,000 and two 5,000 IU vitamin D3 supplements in gelcap form.

Primary Outcome Measures

Name	Time	Method
Fasting glucose level before, mid-way through, and after the vitamin D3 supplement or placebo trial.	16 weeks

Secondary Outcome Measures

Name	Time	Method
Serum 25-OH D levels in response to vitamin D3 supplement or placebo across a range of adiposity	16 weeks

Trial Locations

Locations (1)

Medical College of Georgia; 🇺🇸 Augusta, Georgia, United States