Vitamin K and Glucose Metabolism in Adults at Risk for Diabetes (Vita-K 'n' Adults Study)

November 18, 2019 updated by: Norman Pollock, Augusta University

Vitamin K and Glucose Metabolism in Adults at Risk for Diabetes

Given that glutamate carboxylation or decarboxylation is key to the metabolic role of osteocalcin (at least in mouse models) and that carboxylation is vitamin K dependent, it is critical to isolate the effect of vitamin K manipulation on carboxylation of osteocalcin and its subsequent effect on glucose metabolism in clinical trials. The purpose of this randomized, double-blind, placebo-controlled clinical trial in adults is to determine whether eight weeks of daily supplementation with vitamin K2 (menaquinone-7) can improve markers in blood associated with diabetes risk.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Anticipated)

30

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
    • Georgia
      • Augusta, Georgia, United States, 30912
        • Medical College of Georgia; Augusta University

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

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Healthy adults between 18 and 65 years old
  2. Subject understands the study protocol and agrees to comply with it
  3. Informed Consent Form signed by the subject

Exclusion Criteria:

  1. Subjects using vitamin supplements containing vitamin k
  2. Subjects with (a history of) metabolic or gastrointestinal diseases including hepatic disorders
  3. Subjects presenting chronic degenerative and/or inflammatory diseases
  4. Subjects receiving systemic treatment or topical treatment likely to interfere with evaluation of the study parameters (salicylates, antibiotics)
  5. Subjects receiving corticosteroid treatment
  6. Subjects using oral anticoagulants
  7. Subjects with a history of soy allergy
  8. Subjects who have participated in a clinical study more recently than one month before the current study

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: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo-Control
The placebo-control group will take two placebo softgel capsules every day for 8 weeks.
Dietary supplement: Placebo
Two placebo softgel capsules (containing no vitamin K2) every day for 8 weeks.
Active Comparator: Low-Dose Vitamin K2 (90-mcg/d)
The low-dose vitamin K group will take one 90-mcg vitamin K2 (menaquinone-7) softgel capsule and one placebo softgel capsule every day for 8 weeks.
Dietary supplement: Low-Dose Vitamin K2 Supplement (menaquinone-7; 90-mcg/d)
One 90-mcg vitamin K2 softgel capsules (containing no vitamin K2) and one placebo softgel capsule everyday for 8 weeks.
Active Comparator: High-Dose Vitamin K2 (180-mcg/d)
The high-dose vitamin K group will take two 90-mcg vitamin K2 (menaquinone-7) softgel capsules every day for 8 weeks.
Dietary supplement: High-Dose Vitamin K2 Supplement (menaquinone-7; 180-mcg/d)
Two 90-mcg vitamin K2 softgel capsules every day for 8 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in insulin sensitivity
Time Frame: Change from baseline in insulin sensitivity at 8 weeks
Insulin sensitivity will be calculated from plasma insulin and glucose concentrations measured during a 2-hour oral glucose tolerance test by using the oral glucose minimal model.
Change from baseline in insulin sensitivity at 8 weeks
Change in beta-cell function
Time Frame: Change from baseline in beta-cell function at 8 weeks
Beta-cell function, as assessed by dynamic beta-cell responsitivity, will be calculated from plasma glucose and C-peptide concentrations measured during a 2-hour oral glucose tolerance test by using the oral C-peptide minimal model.
Change from baseline in beta-cell function at 8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in prothrombin time (PT)
Time Frame: Change from baseline in PT at 8 weeks
Change from baseline in PT at 8 weeks
Change in activated partial thromboplastin time (aPTT)
Time Frame: Change from baseline in aPTT at 8 weeks
Change from baseline in aPTT at 8 weeks
Change in arterial stiffness (PWV)
Time Frame: Change from baseline in arterial stiffness at 8 weeks
Arterial stiffness will be assessed using carotid-femoral pulse wave velocity (PWV) by applanation tonometry.
Change from baseline in arterial stiffness at 8 weeks
Change in endothelial function (FMD)
Time Frame: Change from baseline in endothelial function at 8 weeks
Endothelial function will be assessed using brachial artery flow-mediated dilation (FMD) by ultrasound.
Change from baseline in endothelial function at 8 weeks

Collaborators and Investigators

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

Sponsor

Augusta University

Collaborators

Yale University
University of Alabama at Birmingham
Tufts University

Investigators

  • Principal Investigator: Norman K Pollock, Ph.D., Department of Pediatrics, Medical College of Georgia, Augusta University

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

February 1, 2015

Primary Completion (Anticipated)

June 1, 2020

Study Completion (Anticipated)

June 30, 2020

Study Registration Dates

First Submitted

February 12, 2015

First Submitted That Met QC Criteria

February 12, 2015

First Posted (Estimate)

February 19, 2015

Study Record Updates

Last Update Posted (Actual)

November 20, 2019

Last Update Submitted That Met QC Criteria

November 18, 2019

Last Verified

November 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 620511
  • 16GRNT31090037 (Other Grant/Funding Number: American Heart Association)

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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