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

June 12, 2006
June 13, 2006
March 7, 2016
May 30, 2016
November 27, 2017
May 2006
July 2009   (Final data collection date for primary outcome measure)
Plasma Phylloquinone [ Time Frame: 2 months ]
Plasma phylloquinone in response to phylloquinone depletion and repletion
  • Vitamin K (VK) status markers at VK depletion and repletion
  • Urinary excretion of VK metabolites at VK depletion and repletion
  • Bone turnover markers at VK depletion and repletion
Complete list of historical versions of study NCT00336232 on Archive Site
Not Provided
  • Plasma triglyceride levels at VK depletion and repletion
  • Glucose metabolism measures at VK depletion and repletion
  • Mood assessment at VK depletion and repletion
Not Provided
Not Provided
Determinants of Vitamin K Metabolism
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.
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.
Not Applicable
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
  • Aging
  • Osteoporosis
Drug: Vitamin K
phylloquinone (vitamin K1) 500 mcg daily in third month
Other Name: phylloquinone
Experimental: Diet Intervention
28 day diet low vitamin K, 28 day diet high vitamin K
Intervention: Drug: Vitamin K

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
July 2009
July 2009   (Final data collection date for primary outcome measure)

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
Sexes Eligible for Study: All
18 Years to 90 Years   (Adult, Older Adult)
Contact information is only displayed when the study is recruiting subjects
United States
R01DK069341( U.S. NIH Grant/Contract )
Not Provided
Plan to Share IPD: Yes
Sarah Booth, Tufts University
Tufts University
Not Provided
Principal Investigator: Sarah L Booth, PhD Tufts Medical Center
Tufts University
October 2017

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP