The Effect of Vitamin D Repletion on Insulin Resistance
Primary Purpose
Obesity
Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Vitamin D3 (cholecalciferol)
Sponsored by
About this trial
This is an interventional treatment trial for Obesity focused on measuring Obesity, Metabolism
Eligibility Criteria
Inclusion Criteria:
- Nonsmoking men and women, ages 18-65
- Body mass index (BMI) ≥ 28 kg/m² and within 10% of maximum weight
- Serum 25(OH)D level ≤ 20 ng/ml
- Serum insulin level ≥ 7.2 mU/l
- Willingness to maintain current body weight for the duration of the study
- Willingness to maintain baseline lifestyle activities and routines for the duration of the study
- Willingness 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 (due to the potential effects of these agents on inflammatory markers.)
- Willingness 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.
- If of childbearing potential, willingness to use highly effective contraception for the duration of the study.
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
- Renal disease, as evidenced by a serum creatinine above the upper limit of normal on more than one screening visit
- History of kidney stones
- History of chronic hepatitis, or liver enzymes (AST or ALT) more than 2.5 times the upper limit of normal
- Primary hyperparathyroidism or baseline hypercalcemia from any cause
- Current treatment with over-the-counter or prescription weight loss medications, such as orlistat or sibutramine
- History of bariatric surgery
- Current treatment with any cholesterol-lowering medications, such as statins, niacin, fibrates, or ezetimibe
- Blood pressure ≥ 145/90 after ten minutes of rest on more than one screen visit
- Hyperthyroidism or untreated hypothyroidism. Subjects with chronic, treated, stable hypothyroidism may be included in the study at the discretion of the Principal Investigator.
- Pregnancy, desired pregnancy, or lactation within the study period.
- HIV, Hepatitis B and C
- Medical conditions requiring daily calcium supplementation or antacid use
- Use of medications known to interact with calcium or vitamin D metabolism (bisphosphonates, corticosteroids, thiazide diuretics, cholestyramine, colestipol, mineral oil, phenytoin, barbituates, dititalis glycosides, antacids)
- Subjects with known hypersensitivity to cholecalciferol
- Participation in an investigational drug study within one month of screening
- History, physical, or laboratory findings suggestive of any other medical or psychological condition that would, in the opinion of the principal investigator, make the candidate ineligible for the study
Sites / Locations
- Rockefeller University
Outcomes
Primary Outcome Measures
The primary outcome is change in insulin sensitivity over time, as measured by the glucose clamp, HOMA and OGTT.
Secondary Outcome Measures
Full Information
NCT ID
NCT00606957
First Posted
January 22, 2008
Last Updated
October 12, 2011
Sponsor
Rockefeller University
1. Study Identification
Unique Protocol Identification Number
NCT00606957
Brief Title
The Effect of Vitamin D Repletion on Insulin Resistance
Official Title
The Effect of Vitamin D Repletion on Insulin Resistance
Study Type
Interventional
2. Study Status
Record Verification Date
October 2011
Overall Recruitment Status
Completed
Study Start Date
January 2008 (undefined)
Primary Completion Date
May 2009 (Actual)
Study Completion Date
May 2009 (Actual)
3. Sponsor/Collaborators
Name of the Sponsor
Rockefeller University
4. Oversight
5. Study Description
Brief Summary
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).
Primary Hypotheses:
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.
Secondary Hypotheses:
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.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Obesity
Keywords
Obesity, Metabolism
7. Study Design
Primary Purpose
Treatment
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Masking
None (Open Label)
Allocation
N/A
Enrollment
10 (Anticipated)
8. Arms, Groups, and Interventions
Intervention Type
Dietary Supplement
Intervention Name(s)
Vitamin D3 (cholecalciferol)
Intervention Description
Vitamin D will be taken orally, 10,000 IU (0.25 mg) three times per week.
Primary Outcome Measure Information:
Title
The primary outcome is change in insulin sensitivity over time, as measured by the glucose clamp, HOMA and OGTT.
Time Frame
14 weeks
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
65 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria:
Nonsmoking men and women, ages 18-65
Body mass index (BMI) ≥ 28 kg/m² and within 10% of maximum weight
Serum 25(OH)D level ≤ 20 ng/ml
Serum insulin level ≥ 7.2 mU/l
Willingness to maintain current body weight for the duration of the study
Willingness to maintain baseline lifestyle activities and routines for the duration of the study
Willingness 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 (due to the potential effects of these agents on inflammatory markers.)
Willingness 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.
If of childbearing potential, willingness to use highly effective contraception for the duration of the study.
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
Renal disease, as evidenced by a serum creatinine above the upper limit of normal on more than one screening visit
History of kidney stones
History of chronic hepatitis, or liver enzymes (AST or ALT) more than 2.5 times the upper limit of normal
Primary hyperparathyroidism or baseline hypercalcemia from any cause
Current treatment with over-the-counter or prescription weight loss medications, such as orlistat or sibutramine
History of bariatric surgery
Current treatment with any cholesterol-lowering medications, such as statins, niacin, fibrates, or ezetimibe
Blood pressure ≥ 145/90 after ten minutes of rest on more than one screen visit
Hyperthyroidism or untreated hypothyroidism. Subjects with chronic, treated, stable hypothyroidism may be included in the study at the discretion of the Principal Investigator.
Pregnancy, desired pregnancy, or lactation within the study period.
HIV, Hepatitis B and C
Medical conditions requiring daily calcium supplementation or antacid use
Use of medications known to interact with calcium or vitamin D metabolism (bisphosphonates, corticosteroids, thiazide diuretics, cholestyramine, colestipol, mineral oil, phenytoin, barbituates, dititalis glycosides, antacids)
Subjects with known hypersensitivity to cholecalciferol
Participation in an investigational drug study within one month of screening
History, physical, or laboratory findings suggestive of any other medical or psychological condition that would, in the opinion of the principal investigator, make the candidate ineligible for the study
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Allegra Grossman, MD
Organizational Affiliation
The Rockefeller University
Official's Role
Principal Investigator
Facility Information:
Facility Name
Rockefeller University
City
New York
State/Province
New York
ZIP/Postal Code
10021
Country
United States
12. IPD Sharing Statement
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The Effect of Vitamin D Repletion on Insulin Resistance
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