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

Type 2 Diabetes Clinical Trial

— AVIS  

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01141192
• Other study ID #: 0910091
• Status: Completed
• Phase: N/A
• First received: June 4, 2010
• Last updated: June 9, 2010
• Start date: January 2010
• Est. completion date: May 2010

Study information

• Verified date: June 2010
• Source: Georgia Regents University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 48
• Est. completion date: May 2010
• Est. primary completion date: May 2010
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 19 Years to 60 Years

Eligibility

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

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Diabetes Mellitus, Type 2
• Type 2 Diabetes

Intervention

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.
• Inactive comparator
The inactive comparator dose provided was identical in appearance to the active comparator but contained no vitamin D3

Locations

Country	Name	City	State
United States	Medical College of Georgia	Augusta	Georgia

Sponsors (1)

Lead Sponsor	Collaborator
Georgia Regents University

Country where clinical trial is conducted

United States, 

References & Publications (4)

Liu E, Meigs JB, Pittas AG, Economos CD, McKeown NM, Booth SL, Jacques PF. Predicted 25-hydroxyvitamin D score and incident type 2 diabetes in the Framingham Offspring Study. Am J Clin Nutr. 2010 Jun;91(6):1627-33. doi: 10.3945/ajcn.2009.28441. Epub 2010 Apr 14. — View Citation

Liu E, Meigs JB, Pittas AG, McKeown NM, Economos CD, Booth SL, Jacques PF. Plasma 25-hydroxyvitamin d is associated with markers of the insulin resistant phenotype in nondiabetic adults. J Nutr. 2009 Feb;139(2):329-34. doi: 10.3945/jn.108.093831. Epub 2008 Dec 23. — View Citation

Pittas AG, Dawson-Hughes B. Vitamin D and diabetes. J Steroid Biochem Mol Biol. 2010 Jul;121(1-2):425-9. doi: 10.1016/j.jsbmb.2010.03.042. Epub 2010 Mar 18. Review. — View Citation

Voidonikola PT, Stamatelopoulos KS, Alevizaki M, Kollias GE, Zakopoulos NA, Lekakis JP, Anastasiou E, Theodorakis MJ, Pittas AG, Papamichael CM. The association between glycemia and endothelial function in nondiabetic individuals: the importance of body weight. Obesity (Silver Spring). 2008 Dec;16(12):2658-62. doi: 10.1038/oby.2008.431. Epub 2008 Oct 9. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Fasting glucose level before, mid-way through, and after the vitamin D3 supplement or placebo trial.		16 weeks	No
Secondary	Serum 25-OH D levels in response to vitamin D3 supplement or placebo across a range of adiposity		16 weeks	Yes