Osteo Arthritis KneeNCT05505552
Effects of Vitamin K on Lower-extremity Function in Adults With Osteoarthritis:
A study testing Vitamin K in people with Osteo Arthritis Knee, run by Tufts University at 3 sites in United States.
Trial summary
The overall goal of this pilot randomized trial is to obtain necessary prerequisite data to conduct a randomized controlled intervention to test the effect of vitamin K supplementation on knee osteoarthritis progression and related functional decline. Read more about this study
- Who is it for?
- Ages 50 years and older
- Conditions the study is for
- Osteo Arthritis Knee
- What is being tested?
- Vitamin K
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 37 participants
- Where
- 3 sitesUnited States
- Study dates
- 20 Sep 2023to 31 Dec 2026
- 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 50 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 50 years
- Male or post-menopausal female (no menses in the last year)
- Plasma phylloquinone <1.0 nmol/L
- Chronic knee discomfort based on affirmative response to the question "During the past 12 months, have you had pain, aching, or stiffness in or around your knee(s) on most days for at least one month?"
- Kellgren-Lawrence (KL) grade 2-3 in at least one knee
- Ability to understand study procedures and to comply with them for the entire length of the study
- Ability to answer questions by phone
- Ability to swallow capsules
Who cannot join
- KL grade 4 in at least one knee
- Inability to walk
- Cognitive impairment (based on a Montreal Cognitive Assessment Test score ≤ 17)
- Widespread pain
- Malabsorption disorders (e.g. advance liver disease, stage 4 or 5 chronic renal disease, Crohn's disease, celiac sprue)
- Serious medical conditions or impairments that, in the view of the investigator, would obstruct study participation
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- Plan to permanently relocate from the greater Boston, MA or Chapel Hill NC areas during the trial period
- Planned knee or hip arthroplasty during the study period
- Undergoing cancer treatment
- < 50 years old
- Circulating phylloquinone ≥ 1.0 nmol/L
- Warfarin (Jantoven) use
- Use of other investigational drugs
- Use of herbal, botanical or vitamin K supplements
- Use of assistive walking devices
Trial locations and contacts
3 sites in 1 country.
United States3 sites
Tufts University
Boston, Massachusetts, 02111
University of North Carolina Chapel Hill
Chapel Hill, North Carolina, 27599
UMass Memorial Medical Center
Worcester, Massachusetts, 01605
About this study
Official title: Effects of Vitamin K on Lower-extremity Function in Adults With Osteoarthritis: A Randomized Controlled Pilot Trial
The overall goal of this pilot randomized trial is to obtain necessary prerequisite data to conduct a randomized controlled intervention to test the effect of vitamin K supplementation on knee osteoarthritis progression and related functional decline. To address critical parameters required to design this larger RCT, we will conduct a double-blind, 2-armed, parallel-group intervention study, with a placebo run-in, in which 50 adults with mild to moderate knee OA and low baseline vitamin K status will be randomly assigned to 1 mg phylloquinone/day or matching placebo, and treated for 6 months. Specifically, we will: (1) compare the effects of 1 mg/day phylloquinone vs. placebo on the non-functional circulating form of MGP; (2) estimate rates of recruitment and retention, follow-up rates and reasons for loss to follow-up, response rates to questionnaires, adherence/compliance rates, and potential for site differences; and (3) determine the responsiveness of the Osteoarthritis Research Society International (OARSI)-recommended performance-based tests of physical function in adults with low vitamin K status and mild to moderate knee osteoarthritis. We will also obtain preliminary data on the distribution of MGP genotype at two clinical sites for effect size generation.
As of February 2025, based on attrition rate below what was initially expected, we revised our planned enrollment from 50 to 35, to achieve the original goal of 30 completers. This was approved by the study sponsor.
- Conditions
- Osteo Arthritis Knee
- Being tested
- Vitamin K, Placebo
- Keywords
- osteoarthritis, physical function, nutrition
- Medical subject headings
- Osteoarthritis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vitamin KDietary supplement
Also called Phylloquinone
1 mg/day phylloquinone (vitamin K1)
PlaceboDietary supplement
Placebo capsule once daily
| Study group | Role | What they receive |
|---|---|---|
| Vitamin K | Experimental | Participants receive 1 mg/d phylloquinone orally for 24 weeks Receives: Dietary Supplement: Vitamin K |
| Placebo | Placebo comparator | Participants receive daily placebo matching phylloquinone for 24 weeks Receives: Dietary Supplement: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Plasma uncarboxylated matrix gla protein
Plasma uncarboxylated matrix gla protein is considered a functional indicator of vitamin K status. We will evaluate how it changes in response to 1 mg/d vitamin K supplementation in adults with low vitamin K status at baseline and with radiographic knee OA.
Measured: 24 weeks
Secondary outcomes (1)
Plasma phylloquinone
Circulating phylloquinone is considered a global indicator of vitamin K status. We will evaluate how it changes in response to 1 mg/d vitamin K supplementation in adults with low vitamin K status at baseline and with radiographic knee OA.
Measured: 24 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Aug 2022
- Study start20 Sep 2023
- Primary completion30 Apr 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Osteo Arthritis KneeStudies of the same condition, open and under way.
- 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
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 37 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tufts University
- Sponsor type
- University, hospital or other
- Collaborators
- University of North Carolina, Chapel Hill, Tufts Medical Center, University of Massachusetts, Worcester
- Responsible party
- Principal investigator, Sarah Booth, Tufts University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05505552
- Sponsor's protocol ID
- R21AR080297
- Status last verified
- Sep 2025
- First submitted
- 15 Aug 2022
- Last updated
- 17 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Vitamin K on Lower-extremity Function in Adults With Osteoarthritis: A Randomized Controlled Pilot Trial
- ClinicalTrials.gov ID
- NCT05505552
- Acronym / sponsor ID
- R21AR080297
- Conditions
- Osteo Arthritis Knee
- Keywords
- osteoarthritis, physical function, nutrition
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 37 participants (actual)
- Lead sponsor
- Tufts UniversityUniversity, hospital or other
- Collaborators
- University of North Carolina, Chapel Hill, Tufts Medical Center, University of Massachusetts, Worcester
- Study start
- 20 Sep 2023 (actual)
- Primary completion
- 30 Apr 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 17 Aug 2022 (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.
The overall goal of this pilot randomized trial is to obtain necessary prerequisite data to conduct a randomized controlled intervention to test the effect of vitamin K supplementation on knee osteoarthritis progression and related functional decline. To address critical parameters required to design this larger RCT, we will conduct a double-blind, 2-armed, parallel-group intervention study, with a placebo run-in, in which 50 adults with mild to moderate knee OA and low baseline vitamin K status will be randomly assigned to 1 mg phylloquinone/day or matching placebo, and treated for 6 months. Specifically, we will: (1) compare the effects of 1 mg/day phylloquinone vs. placebo on the non-functional circulating form of MGP; (2) estimate rates of recruitment and retention, follow-up rates and reasons for loss to follow-up, response rates to questionnaires, adherence/compliance rates, and potential for site differences; and (3) determine the responsiveness of the Osteoarthritis Research Society International (OARSI)-recommended performance-based tests of physical function in adults with low vitamin K status and mild to moderate knee osteoarthritis. We will also obtain preliminary data on the distribution of MGP genotype at two clinical sites for effect size generation.
As of February 2025, based on attrition rate below what was initially expected, we revised our planned enrollment from 50 to 35, to achieve the original goal of 30 completers. This was approved by the study sponsor.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Vitamin K | Experimental | Dietary Supplement: Vitamin KParticipants receive 1 mg/d phylloquinone orally for 24 weeks |
| Placebo | Placebo comparator | Dietary Supplement: PlaceboParticipants receive daily placebo matching phylloquinone for 24 weeks |
Who may qualify
- Ages
- 50 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Age ≥ 50 years
- Male or post-menopausal female (no menses in the last year)
- Plasma phylloquinone <1.0 nmol/L
- Chronic knee discomfort based on affirmative response to the question "During the past 12 months, have you had pain, aching, or stiffness in or around your knee(s) on most days for at least one month?"
- Kellgren-Lawrence (KL) grade 2-3 in at least one knee
Key exclusion criteria (15 listed)
- KL grade 4 in at least one knee
- Inability to walk
- Cognitive impairment (based on a Montreal Cognitive Assessment Test score ≤ 17)
- Widespread pain
- Malabsorption disorders (e.g. advance liver disease, stage 4 or 5 chronic renal disease, Crohn's disease, celiac sprue)
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 KAlso: Phylloquinone1 mg/day phylloquinone (vitamin K1) | Dietary supplement | Vitamin K |
| PlaceboPlacebo capsule once daily | Dietary supplement | Placebo |
Primary outcome
Plasma uncarboxylated matrix gla protein
Time frame: 24 weeks
Plasma uncarboxylated matrix gla protein is considered a functional indicator of vitamin K status. We will evaluate how it changes in response to 1 mg/d vitamin K supplementation in adults with low vitamin K status at baseline and with radiographic knee OA.
1 secondary outcome
Plasma phylloquinone
Time frame: 24 weeks
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 17 Sep 2025.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
3 sites 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 Osteo Arthritis Knee, run by Tufts University at 3 sites in United States.
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 8 inclusion and 15 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: under way, not looking for participants, as of the sponsor's last update on 17 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States. 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. Some participants in this study may receive a placebo. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Plasma uncarboxylated matrix gla protein (time frame: 24 weeks). 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 17 Sep 2025.