Effect of Vitamin D Supplementation on Oral Glucose Tolerance Among Obese Adolescents

October 6, 2016 updated by: Aneesh Tosh, University of Missouri-Columbia

Effect of 4,000 IU Vitamin D3 Supplementation on Oral Glucose Tolerance Among Vitamin D Deficient Obese Adolescent

Childhood obesity is a rapidly growing epidemic in the US and the world. Current estimates suggest that 30% of our nation's children are either overweight ot obese. Obesity is a major risk factor towards the development of insulin resistance, which, in turn is a major risk factor for the development of type 2 diabetes. Prior research has suggested that vitamin D therapy may be a safe, inexpensive, and effective method of reducing insulin resistance and a person's risk of developing diabetes.

The investigators' prior studies have shown that daily 4,000 IU vitamin D therapy is a safe and effective method of improving insulin resistance based on a calculation called the HOMA-IR.

The next step in identifying whether vitamin D truly improves insulin resistance is to use oral glucose tolerance testing (OGTT), which is a better real-life measure of insulin resistance compared to the previously used HOMA-IR.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The investigators intend to recruit 20 obese adolescent subjects from the PI's obesity clinic to participate in the study. Investigators expect 5 to drop out, therefore leaving 15 subjects to complete the study. Eligible and assenting subjects (with consent from a parent) will be admitting to the Pediatric Procedure Suite and MU Women's and Children's Hospital. They will have an IV placed in the arm by a nurse experienced with working with children. The subjects will have blood drawn from the IV checking for vitamin D level, insulin, glucose, and c-peptide level (another marker for insulin status). The subject will then be asked to drink a 75 gram glucose solution. Additional blood will be drawn from the IV site to check for glucose, insulin, and c-peptide levels at 30 minutes, 60 minutes, 90 minutes, and 120 minutes. A total of 30 mL (2 tablespoons) of blood will be drawn that day. The subject will have the IV removed and will be discharged to then take two 2,000 IU vitamin D3 pills (total 4,000 IU) daily for six months.

At a routine 3 months clinical visit, the subject will be tested for routine, standard of care, basic metabolic profile (BMP) with 4 ml of blood (less than 1 teaspoon) to assess for high calcium levels, a potential complication of vitamin D therapy. In the investigators' previous study of adolescents taking 4,000 IU vitamin D daily for six months, no subject developed a high calcium level.

At six months, the subject will return to the Pediatric procedure suite to have another OGTT and labs via IV as described above.

Study Type

Interventional

Enrollment (Actual)

15

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Missouri
      • Columbia, Missouri, United States, 65201
        • University of Missouri Adolescent Obesity Clinic

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

9 years to 19 years (Child, Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Obese adolescent (BMI >85th percentile for age)
  • 9-19 years of age
  • attending the ADOBE clinic at the University of Missouri
  • 25OH vitamin D level within past 3 months

Exclusion Criteria:

  • use of vit D supplements other than standard multi-vitamin preparation (i.e., should not be receiving vit D > 1000 IU/d)
  • use of medications that interfere with vit D metabolism (e.g., anti-convulsive)
  • history of hepatic or renal disorders, hypercalciuria, or hypercalcemia
  • undergoing UV radiation as medical therapy
  • pregnancy; cigarette smoking; current use of a tanning bed
  • current type 2 diabetes
  • any current antihyperglycemic medication use (e.g. metformin, insulin) less than one month prior to initial OGTT.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 4,000 IU Vitamin D3
two 2,000 IU vitamin D3 pills (total 4,000 IU) daily for six months.
Dietary supplement: 4,000 IU vitamin D3
two 2,000 IU vitamin D3 pills (total 4,000 IU) daily for six months.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
change in oral glucose tolerance
Time Frame: baseline and 6 months
Will obtain oral glucose tolerance tests at baseline and at 6 months to determine change
baseline and 6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Missouri-Columbia

Investigators

  • Principal Investigator: Aneesh K Tosh, MD. MS, University of Missouri-Columbia

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

May 1, 2013

Primary Completion (Actual)

February 1, 2014

Study Completion (Actual)

February 1, 2014

Study Registration Dates

First Submitted

May 10, 2013

First Submitted That Met QC Criteria

May 15, 2013

First Posted (Estimate)

May 20, 2013

Study Record Updates

Last Update Posted (Estimate)

October 10, 2016

Last Update Submitted That Met QC Criteria

October 6, 2016

Last Verified

October 1, 2016

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1203853

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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