An interventional study of Vitamin K and Placebo in Osteo Arthritis Knee, sponsored by Tufts University. Active, not recruiting at 3 sites in United States. Open to participants aged 50 Years and older. Per ClinicalTrials.gov, last updated 2025-09-17.
Sponsored by Tufts University · Not applicable, Interventional, and Other
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.
4,398 studies on the registry are indexed under Osteoarthritis; 582 are open to participants now.
This study's enrollment of 37 is below the median of 70 across 3,440 interventional studies indexed under Osteoarthritis.
Browse Osteoarthritis studies →Tufts University is the lead sponsor of 225 studies on the registry; 24 are open to participants now.
Of its 10 completed or terminated interventional studies of FDA-regulated products, 7 (70%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Participants receive 1 mg/d phylloquinone orally for 24 weeks
Dietary Supplement: Vitamin K
Participants receive daily placebo matching phylloquinone for 24 weeks
Dietary Supplement: Placebo
1 mg/day phylloquinone (vitamin K1)
Also known as: Phylloquinone
Placebo capsule once daily
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.
Time frame: 24 weeks
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.
Time frame: 24 weeks
Lower-extremity function - self reported
The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function index is a disease-specific, self-administered questionnaire, for assessing health status and health outcomes in osteoarthritis of the knee and/or hip. WOMAC function scores range from 0-68, with lower scores reflecting better function.
Time frame: 12 and 24 weeks
Lower-extremity function - objective measures
40-m fast gait speed, Chair stand test, Stair climb test, Timed-up-and-go test, 6 min walk test are measures of lower-extremity function recommended by the Osteoarthritis Research Society International to test physical performance in people with knee OA.
Time frame: 24 weeks
Knee pain
Knee pain, which is symptomatic of OA, will be evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Measurement of Intermittent and Constant Osteoarthritis Pain (ICOAP) self-reported questionnaires. WOMAC pain scores range from 0-20, with higher scores reflecting more pain. ICOAP scores range from 0-100, with higher scores reflecting more pain.
Time frame: 12 and 24 weeks
Plan to share: No
No publications or documents are linked to this record.
This study is active, not recruiting, as verified in Sep 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Tufts University