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Determinants of Vitamin K Metabolism

This study has been completed.
Information provided by (Responsible Party):
Sarah Booth, Tufts University Identifier:
First received: June 12, 2006
Last updated: April 22, 2016
Last verified: April 2016
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 Intervention
Drug: Vitamin K

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Dietary and Non-dietary Components of Vitamin K Metabolism

Resource links provided by NLM:

Further study details as provided by Tufts University:

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

Enrollment: 59
Study Start Date: May 2006
Study Completion Date: July 2009
Primary Completion Date: July 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

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.

Ages Eligible for Study:   18 Years to 90 Years   (Adult, Senior)
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
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Please refer to this study by its identifier: NCT00336232

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
Principal Investigator: Sarah L Booth, PhD Tufts Medical Center
  More Information

Additional Information:
Responsible Party: Sarah Booth, Senior Scientist, Tufts University Identifier: NCT00336232     History of Changes
Other Study ID Numbers: R01DK069341 ( US NIH Grant/Contract Award Number )
Study First Received: June 12, 2006
Results First Received: March 7, 2016
Last Updated: April 22, 2016
Individual Participant Data  
Plan to Share IPD: Yes

Keywords provided by Tufts University:
Vitamin K metabolism
Bone health

Additional relevant MeSH terms:
Bone Diseases, Metabolic
Bone Diseases
Musculoskeletal Diseases
Vitamin K 1
Vitamin K
Growth Substances
Physiological Effects of Drugs
Antifibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Coagulants processed this record on April 21, 2017