Bioavailability of Vitamin KBioMicroNCT07041645
Bioavailability of Different Vitamin K Vitamers Studied Using 13C-labelled Vitamin K Vitamers
A study testing Vitamin K in people with Bioavailability of Vitamin K, run by University of Copenhagen at 1 site in Denmark.
Trial summary
Objectives The main objectives are: Study part I: to investigate the bioavailability of vitamin K vitamers (PK, MK-4, MK-7 and MK-9) in humans using 13C-labelled compounds Hypotheses Study part I: it is hypothesized that there is a difference between the bioavailability of the different vitamers, with MK-9 having the… Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Bioavailability of Vitamin K
- What is being tested?
- Vitamin K
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteDenmark
- Study dates
- 1 Jul 2025to 30 Jun 2031
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Men and women
- Between 18 and 65 years old (including both 18 and 65 year olds)
- Danish-speaking
- Willingness to consume/comply with consumption of study-related intervention products/diet
- Willing to take 10 µg vitamin D3/day and omit intake of all other (vitamins and mineral) supplements before and during the trial
- BMI ≤ 30.0 kg/m2
Who cannot join
- Daily smokers/users of all kinds of nicotine-containing products. Occasional smokers/user can be included if they are willing to refrain from all kinds of nicotine-containing products during the trial (from screening to end of trial)
- Blood donation <3 months prior to study-related blood sampling
- Intensive physical training (> 10 hours of strenuous physical activity per week)
- Participation in other clinical studies at the time of the study
- Pregnant, lactating or planning to become pregnant within the study period
- Habitual alcohol intake above current recommendation (> 10 alcoholic units/week)
Show all 18Show fewer
- History of cancer within the past five (5) years except basal cell skin cancer and cervix
- Diagnosed with chronic inflammation disorders
- Diagnosed with gastrointestinal diseases
- Diagnosed with bone related diseases
- Diagnosed with psychiatric disorder including depression that requires medical treatment
- Medical treatment of diabetes
- Medical treatment of cardiovascular related disease
- Surgical change of the gastrointestinal tract (removal of appendix is allowed)
- Use of prescription medication that can affect their safety or impact on data
- Inability, physically or mental, to comply with the procedure required by the study protocol and evaluated by the principal investigator (PI), study manager or clinical responsible
- Medical treatment with anticoagulation medication (warfarin-like types)
- Allergy or intolerance related to intervention products
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Denmark1 site
University of Copenhagen
Frederiksberg C, 1958
Marie B Jensen, PhD, 26445895, mariebj@nexs.ku.dk
Susanne G Bügel, Professor, 35332490, shb@nexs.ku.dk
About this study
Official title: Bioavailability of Micronutrients With a Special Focus on Vitamin K - Study Part I: K-vitamin
Objectives
The main objectives are:
Read more
Study part I: to investigate the bioavailability of vitamin K vitamers (PK, MK-4, MK-7 and MK-9) in humans using 13C-labelled compounds
Hypotheses Study part I: it is hypothesized that there is a difference between the bioavailability of the different vitamers, with MK-9 having the highest bioavailability followed by MK-7, and then PK, while MK-4 will have the lowest bioavailability.
Participants will:
Study part I: In the pilot study and study part I, participants will visit NEXS for a test period where a 6.5-hour test day will be carried out and followed up with two short visits on the 2 consecutive days. In the pilot study, there will be one test period with frequent blood sampling (before and after ingestion of a labelled vitamin K vitamer) and urine and faeces sampling. The minimum duration for each participant in the pilot study will be 2.5 weeks. After analyses of the bioavailability of the vitamin K vitamers in the pilot study, results will be used to determine the time points for biological sampling (mainly blood) in study part I. Study part I is a cross-over study with 4 test periods and washout periods in between. The minimum duration for each participant will be 6 weeks.
Read the detailed description
Overall study design Pilot study (n= 2 completers): An acute postprandial randomised parallel study comparing the bioavailability of two forms of labelled vitamin K vitamers (13C-PK and 13C-MK-7) Study part I (n= 16 completers): An acute postprandial randomised cross-over study comparing the bioavailability of four forms of labelled vitamin K vitamers (13C-PK, 13C-MK-4, 13C-MK-7, and 13C-MK-9)
Detailed study design of pilot study and part I Prerequisites
Prior to the first test period (day 0) the participants will be asked to:
- 2 weeks before: supplement with 10 µg vitamin D3/day (recommended daily intake) and restrain from all other types of (vitamins and mineral) supplementation
- 1 week before: not consume sweet corns, beetroot and spinach
- 48 hours before: alcohol intake is prohibited
- 24 hours before: high-intensity physical activity is prohibited
- 12 hours before: except 0.5 L tap water, consumption of drinks and foods are not allowed After the first test day and during the remaining part of the study, the participants are asked to refrain from consumption of sweet corn, beetroot and spinach, continue supplementation with vitamin D. Before all days with blood sampling (3 first days in a test period), the above prerequisites related to alcohol intake, high-intensity physical activity and fasting are applicable.
Test periods A baseline description (e.g. anthropometry, blood pressure and fasting values) of the participants will be established prior to and on the first test day (Day 0).
In the pilot study, there will be one test period (Day 0-2) and in the study part I there will be four test periods (Day 0-2, 7-9, 14-15 and 21-23). Except for a few baseline outcomes only collected at Day 0, all test periods will follow the same overall design.
On the first day in a test period (e.g. Day 0), the participants will arrive fasting at NEXS, where a peripheral venous catheter (PVC) will be placed. The participants will rest for 10 minutes before the first blood sample will be taken in the fasting state ("0" minutes). The participants will hereafter have 15 minutes to ingest a breakfast meal containing a 13C-labelled vitamin K vitamer. Postprandial blood samples will hereafter be collected during a 5.5-hour period at the following time points after the breakfast was initiated: 15, 30, 45, 60, 90, 150, 210, 270 and 330 minutes. Furthermore, on the 2 consecutive days a fasting blood sample will be collected corresponding to 24 (±2) hours and 48 (±2) hours after the ingestion of the 13C-labelled vitamin K vitamer.
Results from the pilot study will be used to decide which biological sampling time points that are necessary in study part I where a maximum blood volume per test period will be 125 mL (for all 4 test periods the maximum blood volume will be 500 mL).
Wash out period Participants in the pilot study will have one washout period and participants in study part I will have 4 washout periods. During washout, the participants do not ingest the 13C-labelled vitamin K vitamer. In part I, the washout periods are minimum 6 days to ensure no carry over to the next administration period. Optimally, these washout periods will be planned at days: 1-6 (test period
1), 8-13 (test period 2), 15-20 (test period 3) and 22-27 (test period 4) and the participants will continue the collection of urine and faecal samples during the washout period. On day 7, participants in part I will repeat the test period (except the run-in period) and thus it continues until all 4 vitamin K vitamers have been tested.
In case of illness, vacations, holidays or practical project management reasons, the washout period can be extended. Extension of the washout period is not defined as a protocol deviation if all biological samples are collected on the consecutive days according to time points/definitions.
- Conditions
- Bioavailability of Vitamin K
- Being tested
- Vitamin K
- Keywords
- Bioavailability, vitamin K, 13C-labelled vitamin K
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vitamin KDietary supplement
each participant will recive one dose of each of the four vitamin K vitamers but in different orders (4 different orders).
| Study group | Role | What they receive |
|---|---|---|
| 13C-phylloquinone (13C-PK) | Experimental | The participants will receive one dose of 13C-PK and the levels in blood, urine and feces will be analyzed Receives: Dietary Supplement: Vitamin K |
| 13C-menaquinone-4 (13C-MK-4) | Experimental | The participants will receive one dose of 13C-MK-4 and the levels in blood, urine and feces will be analyzed Receives: Dietary Supplement: Vitamin K |
| 13C-menaquinone-7 (13C-MK-7) | Experimental | The participants will receive one dose of 13C-MK-7 and the levels in blood, urine and feces will be analyzed Receives: Dietary Supplement: Vitamin K |
| 13C-menaquinone-9 (13C-MK-9) | Experimental | The participants will receive one dose of 13C-MK-9 and the levels in blood, urine and feces will be analyzed Receives: Dietary Supplement: Vitamin K |
What is being measured
The primary outcome is the main question the study is designed to answer.
13C-labelled vitamin K vitamers in blood samples
The area under the curve for the different 13C-labelled vitamin K vitamers will be compared from blood samples.
Measured: from test day 1 until the end of the last washout period 5 weeks after test day 1.
13C-labelled vitamin K vitamers in fecal samples
The amount of 13C-labelled vitamin K vitamers in the feces will be analysed
Measured: from test day 1 until the end of the last washout period 5 weeks after test day 1.
13C-lebelled vitamin K vitamers in urine samples
The amount of 13C-labelled vitamin K vitamers in the urine will be analysed
Measured: from test day 1 until the end of the last washout period 5 weeks after test day 1.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jun 2025
- Study start1 Jul 2025 (estimated)
- Primary completionDec 2026 (estimated)
- Study completion30 Jun 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bioavailability of Vitamin KStudies of the same condition, open and under way.
- More trials run by University of CopenhagenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Copenhagen
- Sponsor type
- University, hospital or other
- Collaborators
- Technical University of Denmark
- Responsible party
- Principal investigator, Susanne Bügel, University of Copenhagen
- Investigators
- Susanne G Bügel, Professor, Principal investigator, University of Copenhagen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07041645
- Sponsor's protocol ID
- BioMicro Protokol v1.2
- Acronym
- BioMicro
- Status last verified
- Jun 2025
- First submitted
- 19 Jun 2025
- Last updated
- 27 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: We will report anonymized data for publications of the result.
Study at a glance
From the registry record, last updated by the sponsor on 27 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Bioavailability of Micronutrients With a Special Focus on Vitamin K - Study Part I: K-vitamin
- ClinicalTrials.gov ID
- NCT07041645
- Acronym / sponsor ID
- BioMicro / BioMicro Protokol v1.2
- Conditions
- Bioavailability of Vitamin K
- Keywords
- Bioavailability, vitamin K, 13C-labelled vitamin K
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of CopenhagenUniversity, hospital or other
- Collaborators
- Technical University of Denmark
- Study start
- 1 Jul 2025 (estimated)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- 30 Jun 2031 (estimated)
- First posted
- 27 Jun 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Objectives
The main objectives are:
Study part I: to investigate the bioavailability of vitamin K vitamers (PK, MK-4, MK-7 and MK-9) in humans using 13C-labelled compounds
Hypotheses Study part I: it is hypothesized that there is a difference between the bioavailability of the different vitamers, with MK-9 having the highest bioavailability followed by MK-7, and then PK, while MK-4 will have the lowest bioavailability.
Participants will:
Study part I: In the pilot study and study part I, participants will visit NEXS for a test period where a 6.5-hour test day will be carried out and followed up with two short visits on the 2 consecutive days. In the pilot study, there will be one test period with frequent blood sampling (before and after ingestion of a labelled vitamin K vitamer) and urine and faeces sampling. The minimum duration for each participant in the pilot study will be 2.5 weeks. After analyses of the bioavailability of the vitamin K vitamers in the pilot study, results will be used to determine the time points for biological sampling (mainly blood) in study part I. Study part I is a cross-over study with 4 test periods and washout periods in between. The minimum duration for each participant will be 6 weeks.
Detailed description
Overall study design Pilot study (n= 2 completers): An acute postprandial randomised parallel study comparing the bioavailability of two forms of labelled vitamin K vitamers (13C-PK and 13C-MK-7) Study part I (n= 16 completers): An acute postprandial randomised cross-over study comparing the bioavailability of four forms of labelled vitamin K vitamers (13C-PK, 13C-MK-4, 13C-MK-7, and 13C-MK-9)
Detailed study design of pilot study and part I Prerequisites
Prior to the first test period (day 0) the participants will be asked to:
- 2 weeks before: supplement with 10 µg vitamin D3/day (recommended daily intake) and restrain from all other types of (vitamins and mineral) supplementation
- 1 week before: not consume sweet corns, beetroot and spinach
- 48 hours before: alcohol intake is prohibited
- 24 hours before: high-intensity physical activity is prohibited
- 12 hours before: except 0.5 L tap water, consumption of drinks and foods are not allowed After the first test day and during the remaining part of the study, the participants are asked to refrain from consumption of sweet corn, beetroot and spinach, continue supplementation with vitamin D. Before all days with blood sampling (3 first days in a test period), the above prerequisites related to alcohol intake, high-intensity physical activity and fasting are applicable.
Test periods A baseline description (e.g. anthropometry, blood pressure and fasting values) of the participants will be established prior to and on the first test day (Day 0).
In the pilot study, there will be one test period (Day 0-2) and in the study part I there will be four test periods (Day 0-2, 7-9, 14-15 and 21-23). Except for a few baseline outcomes only collected at Day 0, all test periods will follow the same overall design.
On the first day in a test period (e.g. Day 0), the participants will arrive fasting at NEXS, where a peripheral venous catheter (PVC) will be placed. The participants will rest for 10 minutes before the first blood sample will be taken in the fasting state ("0" minutes). The participants will hereafter have 15 minutes to ingest a breakfast meal containing a 13C-labelled vitamin K vitamer. Postprandial blood samples will hereafter be collected during a 5.5-hour period at the following time points after the breakfast was initiated: 15, 30, 45, 60, 90, 150, 210, 270 and 330 minutes. Furthermore, on the 2 consecutive days a fasting blood sample will be collected corresponding to 24 (±2) hours and 48 (±2) hours after the ingestion of the 13C-labelled vitamin K vitamer.
Results from the pilot study will be used to decide which biological sampling time points that are necessary in study part I where a maximum blood volume per test period will be 125 mL (for all 4 test periods the maximum blood volume will be 500 mL).
Wash out period Participants in the pilot study will have one washout period and participants in study part I will have 4 washout periods. During washout, the participants do not ingest the 13C-labelled vitamin K vitamer. In part I, the washout periods are minimum 6 days to ensure no carry over to the next administration period. Optimally, these washout periods will be planned at days: 1-6 (test period
1), 8-13 (test period 2), 15-20 (test period 3) and 22-27 (test period 4) and the participants will continue the collection of urine and faecal samples during the washout period. On day 7, participants in part I will repeat the test period (except the run-in period) and thus it continues until all 4 vitamin K vitamers have been tested.
In case of illness, vacations, holidays or practical project management reasons, the washout period can be extended. Extension of the washout period is not defined as a protocol deviation if all biological samples are collected on the consecutive days according to time points/definitions.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| 13C-phylloquinone (13C-PK) | Experimental | Dietary Supplement: Vitamin KThe participants will receive one dose of 13C-PK and the levels in blood, urine and feces will be analyzed |
| 13C-menaquinone-4 (13C-MK-4) | Experimental | Dietary Supplement: Vitamin KThe participants will receive one dose of 13C-MK-4 and the levels in blood, urine and feces will be analyzed |
| 13C-menaquinone-7 (13C-MK-7) | Experimental | Dietary Supplement: Vitamin KThe participants will receive one dose of 13C-MK-7 and the levels in blood, urine and feces will be analyzed |
| 13C-menaquinone-9 (13C-MK-9) | Experimental | Dietary Supplement: Vitamin KThe participants will receive one dose of 13C-MK-9 and the levels in blood, urine and feces will be analyzed |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Men and women
- Between 18 and 65 years old (including both 18 and 65 year olds)
- Danish-speaking
- Willingness to consume/comply with consumption of study-related intervention products/diet
- Willing to take 10 µg vitamin D3/day and omit intake of all other (vitamins and mineral) supplements before and during the trial
Key exclusion criteria (18 listed)
- Daily smokers/users of all kinds of nicotine-containing products. Occasional smokers/user can be included if they are willing to refrain from all kinds of nicotine-containing products during the trial (from screening to end of trial)
- Blood donation <3 months prior to study-related blood sampling
- Intensive physical training (> 10 hours of strenuous physical activity per week)
- Participation in other clinical studies at the time of the study
- Pregnant, lactating or planning to become pregnant within the study period
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Vitamin Keach participant will recive one dose of each of the four vitamin K vitamers but in different orders (4 different orders). | Dietary supplement | 13C-menaquinone-4 (13C-MK-4), 13C-menaquinone-7 (13C-MK-7), 13C-menaquinone-9 (13C-MK-9), 13C-phylloquinone (13C-PK) |
Primary outcome
13C-labelled vitamin K vitamers in blood samples
Time frame: from test day 1 until the end of the last washout period 5 weeks after test day 1.
The area under the curve for the different 13C-labelled vitamin K vitamers will be compared from blood samples.
13C-labelled vitamin K vitamers in fecal samples
Time frame: from test day 1 until the end of the last washout period 5 weeks after test day 1.
The amount of 13C-labelled vitamin K vitamers in the feces will be analysed
13C-lebelled vitamin K vitamers in urine samples
Time frame: from test day 1 until the end of the last washout period 5 weeks after test day 1.
The amount of 13C-labelled vitamin K vitamers in the urine will be analysed
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Jun 2025.
- Individual participant dataSharing planned: No. We will report anonymized data for publications of the result.
Related trials for Bioavailability of Vitamin K
Not yet recruiting
Bioavailability of Micronutrients With a Special Focus on Vitamin K Dependent on Consumed Diet
Micronutrient Status
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Susanne G Bügel, Professor principal investigator
University of Copenhagen
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Vitamin K in people with Bioavailability of Vitamin K, run by University of Copenhagen at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 27 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Susanne Gjedsted Bügel, PhD (35332490, shb@nexs.ku.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
13C-labelled vitamin K vitamers in blood samples (time frame: from test day 1 until the end of the last washout period 5 weeks after test day 1.). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Jun 2025.