Trial Information

Summary: 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).

We will first do blood tests to determine whether your vitamin D level is low and whether there is evidence of glucose intolerance. If both states exist we will invite you to partake in the study.

Patient Inclusion Criteria:

• You are a non-smoking man or woman between the ages of 18 and 65
• Your body mass index (BMI) is = 28 kg/m² and within 10% of maximum weight
• Your blood vitamin D level is = 20 ng/ml. This will be determined by your screening blood work.
• You are willing to maintain current body weight for the duration of the study
• You are willing to maintain baseline lifestyle activities and routines for the duration of the study
• You are willing to avoid the use of non-steroidal anti-inflammatory drugs (NSAIDS), including low-dose daily aspirin, for at least ten days prior to each admission. These medications can interfere with the endpoints the investigators are looking at.
• You are willing to avoid the use of all over-the-counter or prescription vitamins, dietary supplements, and herbal products during the study, with the exception of a basic multivitamin supplement.
• You are willing to use highly effective birth control for the duration of the study, if you are a woman who can become pregnant

Patient Exclusion Criteria:

• Current tobacco smoking
• History of bleeding or coagulation disorders
• Gastrointestinal disease resulting in significant gastrointestinal dysfunction or malabsorption
• History of diabetes, or diagnosed during screening OGTT
• Current treatment with hypertensive medications
• History of cardiovascular disease
• HIV, Hepatitis B and C

Primary Outcomes: The primary outcome is change in insulin sensitivity over time, as measured by the glucose clamp, HOMA and OGTT.

If you would like to learn more about participating in this study, please send an e-mail message using the form below.