Back to results

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)

About this trial

This is an interventional treatment trial for Obesity focused on measuring Obesity, Metabolism

Eligibility Criteria

18 Years - 65 Years (Adult, Older Adult)All SexesAccepts Healthy Volunteers

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

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

Learn more about this trial

The Effect of Vitamin D Repletion on Insulin Resistance

We'll reach out to this number within 24 hrs