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Determinants of Vitamin K Metabolism

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00336232
Recruitment Status : Completed
First Posted : June 13, 2006
Results First Posted : May 30, 2016
Last Update Posted : November 27, 2017
Information provided by (Responsible Party):
Sarah Booth, Tufts University

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Aging Osteoporosis Drug: Vitamin K Not Applicable

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 59 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Dietary and Non-dietary Components of Vitamin K Metabolism
Study Start Date : May 2006
Actual Primary Completion Date : July 2009
Actual Study Completion Date : July 2009

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin K

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 Name: phylloquinone

Primary Outcome Measures :
  1. Plasma Phylloquinone [ Time Frame: 2 months ]
    Plasma phylloquinone in response to phylloquinone depletion and repletion

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 90 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00336232

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United States, Massachusetts
Jean Mayer United States Department of Agriculture Human Nutrition Research Center on Aging at Tufts University
Boston, Massachusetts, United States, 02111
Sponsors and Collaborators
Tufts University
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Principal Investigator: Sarah L Booth, PhD Tufts Medical Center

Additional Information:
Publications of Results:
Other Publications:
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: Sarah Booth, Senior Scientist, Tufts University Identifier: NCT00336232    
Other Study ID Numbers: R01DK069341 ( U.S. NIH Grant/Contract )
First Posted: June 13, 2006    Key Record Dates
Results First Posted: May 30, 2016
Last Update Posted: November 27, 2017
Last Verified: October 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Keywords provided by Sarah Booth, Tufts University:
Vitamin K metabolism
Bone health
Additional relevant MeSH terms:
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Bone Diseases, Metabolic
Bone Diseases
Musculoskeletal Diseases
Metabolic Diseases
Vitamin K
Vitamin K 1
Growth Substances
Physiological Effects of Drugs
Antifibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action