Effect of Vitamin D Supplementation on Hemoglobin A1c

April 22, 2015 updated by: Prabhat Pokhrel, Ascension Genesys Hospital

Does Vitamin D Supplement Alter Serum Level of Glycosylated Hemoglobin in Adult Patients Between 34-74 Years With Type 2 Diabetes Mellitus and Vitamin D Deficiency?

This is a prospective, randomized, non-blinded interventional study that will investigate the effect of a vitamin D supplement on HbA1c in patients with uncontrolled type 2 diabetes mellitus (DM) and vitamin D deficiency. The goal is to investigate whether correcting vitamin D deficiency will alter the HbA1c level in patients with type 2 DM and lower than normal vitamin D level. My hypothesis is that correcting vitamin D deficiency decreases HbA1c levels in patients with type 2 DM and vitamin D deficiency.

Study Overview

Detailed Description

The total number of study subjects expected to be enrolled in this study is about 150. Study subjects included in this study will be men and women between 34-69 years of age who have been diagnosed with type 2 DM based on at least one of the American Diabetic Association criteria. These criteria are 1) fasting blood glucose higher than 125 mg/dL once with symptoms of diabetes (increased urination, increased appetite, increased thirst) or two times without symptoms; 2) random blood glucose more than 200 mg/dL once with symptoms or two times without symptoms of diabetes; 3) two hour glucose tolerance test more than 200 mg/dL once with symptoms or two times without symptoms; or 4) a random glycosylated hemoglobin more than 6.5 % two times. The age group for this research was selected based on the review of the literature on diabetes and vitamin D. Patients with known primary hyperparathyroidism, sarcoidosis, tuberculosis, cancer, potential terminal illness, history of serum creatinine more than 2.0 mg/dL, vitamin D supplement more than 200 IU/day, inflammatory bowel disease and history of hypercalcemia and kidney stones will be excluded from this study. For this project, vitamin D deficiency is defined as serum vitamin D level lower than 30 ng/mL and uncontrolled diabetes is defined as HbA1C level above 7.0. Although there is more than one recommended normal level of vit. D in the blood, most experts agree that the optimum serum level of vitamin D should be above 30 ng/mL. All subjects will be receiving standard of care for DM offered to them by his or her physician.

The investigators will investigate if different but fixed doses of vitamin D (600 IU a day vs 50,000 IU once every other week) when given to patients with type 2 DM and vitamin D deficiency have different effects on HbA1c level at the end of 24 weeks. A baseline blood draw, and fasting blood draws will be taken at 12 and 24 weeks for blood sugar levels, Vit D levels, and HgbA1c. Subjects with vitamin D deficiency will be randomly assigned to either group 1 or 2 and will be supplemented with either 600 IU of vitamin D/day (Group 1) or 50,000 IU of vitamin D every 2 weeks for 24 weeks (Groups 2). Patients who are not vitamin D deficient will be followed as the control group (Group 3) and will not be given any vitamin D supplement.Research subjects will be advised not to take any vitamin D or multivitamin while participating in this study. Subjects will be given 100 tablets of 600 IU of vitamin D in a bottle if they belong to Group 1. If they have been advised to take vitamin D 50,000 IU once every 14 days (Group 2), they will be given altogether 13 tablets of 50,000 of vitamin D each in a separate brown envelope with date written on the envelop and subjects will be asked to take vitamin D only on the date written on the envelop.

Study Type

Interventional

Enrollment (Actual)

150

Phase

  • Phase 2

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

    • Michigan
      • Flint, Michigan, United States, 48503
        • Genesys East Flint Campus 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

34 years to 69 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Type 2 diabetes mellitus
  • Hgb A1c greater then 7.0
  • Adults aged 34 to 69 years.

Exclusion Criteria:

  • known primary hyperparathyroidism, sarcoidosis, tuberculosis, cancer, potential terminal illness,
  • history of serum creatinine more than 2.0 mg/dL,
  • vitamin D supplement more than 200 IU/day
  • history of inflammatory bowel disease, hypercalcemia or kidney stones

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: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Lower dose vitamin D
Fixed daily doses of 600 IU vitamin D oral supplementation.
600 IU daily oral supplementation
50,000 IU supplementation bi-monthly
Experimental: Higher dose vitamin D
50,000 IU supplementation bi-monthly.
600 IU daily oral supplementation
50,000 IU supplementation bi-monthly
No Intervention: Control Group
Patients will be followed from baseline to 12 and 24 week follow up. Patients do not receive any research treatment or intervention beyond the standard care of their diabetes. This group are patients with normal levels of Vitamin D.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in serum levels of Hemoglobin A1c.
Time Frame: Change from baseline assessed at 12 wk and 24 wk.
Serum levels of hemoglobin A1c will be tested in the laboratory from blood draws conducted at baseline and at 12 and 24 weeks from a fasting blood sample.
Change from baseline assessed at 12 wk and 24 wk.

Collaborators and Investigators

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

Investigators

  • Study Director: Kimberly R Barber, PhD, Ascension Genesys Hospital
  • Principal Investigator: Prabhat K Pokhrel, MD, Ascension Genesys Hospital

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.

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

March 1, 2011

Primary Completion (Actual)

January 1, 2012

Study Completion (Actual)

June 1, 2012

Study Registration Dates

First Submitted

May 13, 2011

First Submitted That Met QC Criteria

May 13, 2011

First Posted (Estimate)

May 16, 2011

Study Record Updates

Last Update Posted (Estimate)

April 23, 2015

Last Update Submitted That Met QC Criteria

April 22, 2015

Last Verified

April 1, 2015

More Information

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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