Determinants of Vitamin K Metabolism

November 27, 2023 updated by: Sarah Booth, Tufts University

Dietary and Non-dietary Components of Vitamin K Metabolism

The purpose of this study is to learn how the body responds to different amounts of vitamin K in the diet in order to understand the roles that vitamin K may have in the body. We also need to determine if older adults need more or less vitamin K in their diet compared to younger adults in order to maintain normal body stores of vitamin K.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Vitamin K has a role in bone health, but little is known about vitamin K metabolism in aging and in maintenance of bone mass. The limited understanding of vitamin K metabolism impedes the establishment of dietary recommendations for vitamin K, and the interpretation of results from clinical trials on vitamin K supplementation and bone health of women in a narrow age group. This study is the first to assess the role of dietary and other factors that influence the response to vitamin K status and bone turnover to vitamin K depletion and repletion in adults. This study also compares the absorption efficiency and body retention of vitamin K relative to current vitamin K status. Men and women [21 younger (18-40y) and 21 older (55+y)] will participate in a 62-d metabolic study, with a 5d run-in period, followed by a 28d dietary vitamin K restriction period (10 ug/d), and ending with a 28d dietary vitamin K supplementation period (500 ug/d). Coagulation times will be monitored during the dietary restriction period. Serial measurements of vitamin K status markers and of bone turnover markers will show the response of vitamin K to dietary manipulation for both age groups under identically controlled dietary conditions. Deuterium-labeled vitamin K in collards will be used to compare the absorption of vitamin K during a vitamin K-deplete state to that of a vitamin K-replete state. Vitamin K is transported in triglyceride-rich lipoproteins, which may vary among individuals due to differences in adiposity and lipid homeostasis. Therefore, measurement of body composition by Dual Energy X-Ray Absorptiometry (DXA) and plasma lipids will provide insight into the role of lipids in absorption and transport of vitamin K. The findings of this study are critical for the interpretation of the epidemiologic and clinical data used to determine the protective role vitamin K may have in chronic disease prevention.

Study Type

Interventional

Enrollment (Actual)

59

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
    • Massachusetts
      • Boston, Massachusetts, United States, 02111
        • Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts 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 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

-

Exclusion Criteria:

  • kidney, GI, or liver disease requiring treatment
  • prescribed osteoporosis medications in the previous 3 months
  • use of acid reducers more than twice per week
  • blood clotting disorder and/or abnormal clotting time
  • warfarin or anticoagulant use in the previous 12 months
  • diabetes
  • smoking
  • hormone therapy in the previous 3 months
  • oral contraceptive use in the previous 3 months; pregnancy
  • strict vegetarian diet

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: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Diet Intervention
28 day diet low vitamin K, 28 day diet high vitamin K
Drug: Vitamin K
phylloquinone (vitamin K1) 500 mcg daily in third month
Other Names:
  • phylloquinone

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Plasma Phylloquinone
Time Frame: 2 months
Plasma phylloquinone in response to phylloquinone depletion and repletion
2 months

Collaborators and Investigators

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

Sponsor

Tufts University

Investigators

  • Principal Investigator: Sarah L Booth, PhD, Tufts Medical Center

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

Helpful Links

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, 2006

Primary Completion (Actual)

July 1, 2009

Study Completion (Actual)

July 1, 2009

Study Registration Dates

First Submitted

June 12, 2006

First Submitted That Met QC Criteria

June 12, 2006

First Posted (Estimated)

June 13, 2006

Study Record Updates

Last Update Posted (Actual)

November 29, 2023

Last Update Submitted That Met QC Criteria

November 27, 2023

Last Verified

November 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • R01DK069341 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

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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