Objectives: Vitamin K (VK) has bone and cartilage effects, and previously shown to be associated with radiographic OA. We evaluated VK’s effect on hand osteoarthritis (OA) in a randomized controlled trial (RCT).
Methods: The was an ancillary study to a RCT assessing the effects of phylloquinone supplementation (VK arm) versus placebo on bone loss and vascular calcification among older adults regardless of their VK status. At the final 3-year study visit, we assessed the effects of VK versus placebo on hand x-ray features of OA using logistic regression and intention to treat, and also restricted analysis to the subgroup that had insufficient VK concentrations at baseline.
Results: This ancillary study had 378 participants (193 in VK arm, 185 in placebo arm). There were no effects of randomization to VK for radiographic OA outcomes. Those with insufficient VK at baseline who attained sufficient concentrations at follow-up had trends towards 47% less joint-space narrowing (p=0.02).
Conclusions: There was no overall effect of VK on radiographic hand OA. Subjects that were insufficient in VK at baseline who attained sufficient concentrations at follow-up may have had a benefit in joint-space narrowing. A clinical trial in those who are VK insufficient may be warranted.