Effects of Vitamin K on Lower-extremity Function in Adults With Osteoarthritis:

NCT05505552 | Active Not Recruiting

• 1 other identifier: R21AR080297
• Study Type: interventional
• Target: 37
• Locations: 1 country
• Sites: 3

Brief 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. 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

Keywords

osteoarthritis; physical function; nutrition

Outcome Measures

Primary Outcomes (1)

• 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.

  24 weeks

Secondary Outcomes (1)

• Plasma phylloquinone

  24 weeks

Other Outcomes (3)

• Lower-extremity function - self reported

  12 and 24 weeks

• Lower-extremity function - objective measures

  24 weeks

• Knee pain

  12 and 24 weeks

Study Arms (2)

Vitamin K

EXPERIMENTAL

Participants receive 1 mg/d phylloquinone orally for 24 weeks

Dietary Supplement: Vitamin K

Placebo

PLACEBO COMPARATOR

Participants receive daily placebo matching phylloquinone for 24 weeks

Dietary Supplement: Placebo

Interventions

Vitamin K DIETARY_SUPPLEMENT

1 mg/day phylloquinone (vitamin K1)

Also known as: Phylloquinone

Vitamin K

Placebo DIETARY_SUPPLEMENT

Placebo capsule once daily

Placebo

Eligibility Criteria

• Age: 50 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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
• 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

Sponsors & Collaborators

• Tufts University: lead
• University of North Carolina, Chapel Hill: collaborator
• Tufts Medical Center: collaborator
• University of Massachusetts, Worcester: collaborator

Study Sites (3)

Tufts University

Boston, Massachusetts, 02111, United States

Location

UMass Memorial Medical Center

Worcester, Massachusetts, 01605, United States

Location

University of North Carolina Chapel Hill

Chapel Hill, North Carolina, 27599, United States

Location

MeSH Terms

Conditions

Osteoarthritis

Interventions

Vitamin K; Vitamin K 1

Condition Hierarchy (Ancestors)

Arthritis; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases

Intervention Hierarchy (Ancestors)

Naphthoquinones; Naphthalenes; Polycyclic Aromatic Hydrocarbons; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons; Organic Chemicals; Phytol; Diterpenes; Terpenes; Polycyclic Compounds; Quinones

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Senior Scientist and Center Director

Study Record Dates

• First Submitted: August 15, 2022
• First Posted: August 17, 2022
• Study Start: September 20, 2023
• Primary Completion: April 30, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: September 17, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (3)