The Effect of Vitamin D Supplementation on Glucose Metabolism in Non-Diabetic African American Adults (AVIS)
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.
|Type 2 Diabetes||Dietary Supplement: vitamin D3, cholecalciferol Dietary Supplement: Inactive comparator|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Investigator)
Primary Purpose: Prevention
|Official Title:||The Effect of Vitamin D Supplementation on Glucose Metabolism in Non-Diabetic African American Adults|
- Fasting glucose level before, mid-way through, and after the vitamin D3 supplement or placebo trial. [ Time Frame: 16 weeks ]
- Serum 25-OH D levels in response to vitamin D3 supplement or placebo across a range of adiposity [ Time Frame: 16 weeks ]
|Study Start Date:||January 2010|
|Study Completion Date:||May 2010|
|Primary Completion Date:||May 2010 (Final data collection date for primary outcome measure)|
Active Comparator: Vitamin D3 supplement
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.
Dietary Supplement: vitamin D3, cholecalciferol
1 gelcap of 50,000 IU vitamin D3 plus 2 gelcaps of 5,000 IU vitamin D3 each; a total of 60,000 IU vitamin D3 dosed four weeks apart at weeks 0, 4, 8, and 12 of the 16 week study.
Placebo Comparator: Sugar Pill
Inactive placebo tablets identical in appearance to the active comparator provided every four weeks at weeks 0,4,8,and 12.
Dietary Supplement: Inactive comparator
The inactive comparator dose provided was identical in appearance to the active comparator but contained no vitamin D3
Please refer to this study by its ClinicalTrials.gov identifier: NCT01141192
|United States, Georgia|
|Medical College of Georgia|
|Augusta, Georgia, United States, 30912|
|Study Director:||Yanbin Dong, MD, PhD||Augusta University|