Status:
COMPLETED
The Effect of Vitamin D Repletion on Insulin Resistance
Lead Sponsor:
Rockefeller University
Conditions:
Obesity
Eligibility:
All Genders
18-65 years
Phase:
NA
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 t...
Eligibility Criteria
Inclusion
- 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
- 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
Key Trial Info
Start Date :
January 1 2008
Trial Type :
INTERVENTIONAL
Allocation :
ESTIMATED
End Date :
May 1 2009
Estimated Enrollment :
10 Patients enrolled
Trial Details
Trial ID
NCT00606957
Start Date
January 1 2008
End Date
May 1 2009
Last Update
October 13 2011
Active Locations (1)
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1
Rockefeller University
New York, New York, United States, 10021