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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.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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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.

Susanne Gjedsted Bügel, PhD contact

35332490

shb@nexs.ku.dk

Susanne G Bügel, Professor contact

35332490

shb@nexs.ku.dk

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

Other trials in Denmark

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.

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 groups in NCT07041645
Study groupRoleWhat they receive
13C-phylloquinone (13C-PK)ExperimentalThe 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)ExperimentalThe 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)ExperimentalThe 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)ExperimentalThe 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.

  1. 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.

  2. 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.

  3. 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.

  1. First posted27 Jun 2025
  2. Study start1 Jul 2025 (estimated)
  3. Primary completionDec 2026 (estimated)
  4. Study completion30 Jun 2031 (estimated)

Resources

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)
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.

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.

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