Aging, Osteoporosis
Conditions
Keywords
Vitamin K metabolism, Bone health, Metabolism
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.
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.
Interventions
DRUGVitamin K
phylloquinone (vitamin K1) 500 mcg daily in third month
Sponsors
Tufts University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 90 Years
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Plasma Phylloquinone | 2 months | Plasma phylloquinone in response to phylloquinone depletion and repletion |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Diet Intervention 5 day baseline vitamin K
Vitamin K: phylloquinone (vitamin K1) 200 mcg daily
28 day diet low vitamin K
Vitamin K: phylloquinone (vitamin K1) approx. 10 mcg daily for 28 days
treatment started day 6, completed day 33
28 day diet high vitamin K
Vitamin K: phylloquinone (vitamin K1) 500 mcg daily in third month
treatment started day 34, ended day 61 | 42 |
| Total | 42 |
Baseline characteristics
| Characteristic | Diet Intervention |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 11 Participants |
| Age, Categorical Between 18 and 65 years | 31 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 40 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Plasma phylloquinone (nmol/L) | 0.8 nmol/L STANDARD_DEVIATION 1.1 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 5 Participants |
| Race (NIH/OMB) Black or African American | 4 Participants |
| Race (NIH/OMB) More than one race | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 32 Participants |
| Region of Enrollment United States | 42 participants |
| Sex: Female, Male Female | 21 Participants |
| Sex: Female, Male Male | 21 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 3 / 42 |
| serious Total, serious adverse events | 0 / 42 |
Outcome results
Primary
Plasma Phylloquinone
Plasma phylloquinone in response to phylloquinone depletion and repletion
Time frame: 2 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Diet Intervention | Plasma Phylloquinone | low vitamin K | 0.3 nmol/L | Standard Deviation 0.6 |
| Diet Intervention | Plasma Phylloquinone | high vitamin K | 2.3 nmol/L | Standard Deviation 1.4 |