The Effect of Vitamin D Repletion on Insulin Resistance
The reason for doing this study is to learn whether raising a person's vitamin D level from below normal to normal levels will improve his or her body's ability to use sugar. Vitamin D is well known to be an important vitamin for the development and maintenance of bones. Recently, scientists have learned that vitamin D may have a role in the prevention of cancer, diabetes, and autoimmune diseases. The investigators are specifically interested in studying this question in the overweight/obese population as they are at greater risk for both vitamin D deficiency and impaired ability to metabolize sugar (glucose intolerance).
Vitamin D repletion (increasing the serum 25(OH)D level from ≤ 20 ng/ml to ≥ 30 ng/ml) will improve insulin sensitivity in individuals who are overweight/obese and insulin resistant.
1.Vitamin D repletion will improve biomarkers of cardiovascular risk and inflammation (directly altering macrophage cytokine production and/or indirectly as a result of improvement in insulin sensitivity.) 2.30,000 IU (0.25 mg) weekly of cholecalciferol (vitamin D3) will raise serum 25(OH)D levels from ≤ 20 ng/ml to ≥ 30 ng/ml overweight/obese population.
|Study Design:||Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||The Effect of Vitamin D Repletion on Insulin Resistance|
- The primary outcome is change in insulin sensitivity over time, as measured by the glucose clamp, HOMA and OGTT. [ Time Frame: 14 weeks ] [ Designated as safety issue: No ]
|Study Start Date:||January 2008|
|Study Completion Date:||May 2009|
|Primary Completion Date:||May 2009 (Final data collection date for primary outcome measure)|
Dietary Supplement: Vitamin D3 (cholecalciferol)
|United States, New York|
|New York, New York, United States, 10021|
|Principal Investigator:||Allegra Grossman, MD||The Rockefeller University|