Vitamin K in hand osteoarthritis: results from a randomised clinical trial.

Author(s): Neogi T, Felson DT, Sarno R, Booth SL

Affiliation(s): Boston University School of Medicine, Boston, MA 02118, USA. tneogi@bu.edu

Publication date & source: 2008-11, Ann Rheum Dis., 67(11):1570-3. Epub 2008 Jul 14.

Publication type: Randomized Controlled Trial; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.

OBJECTIVES: Vitamin K has bone and cartilage effects, and previously shown to be associated with radiographic osteoarthritis. We evaluated vitamin K's effect on hand osteoarthritis in a randomised controlled trial. METHODS: This was an ancillary study to a randomised controlled trial assessing the effects of phylloquinone supplementation (vitamin K arm) versus placebo on bone loss and vascular calcification among older adults regardless of their vitamin K status. At the final 3-year study visit, we assessed the effects of vitamin K versus placebo on hand x-ray features of osteoarthritis using logistic regression and intention to treat, and also restricted analysis to the subgroup that had insufficient vitamin K concentrations at baseline. RESULTS: This ancillary study had 378 participants (193 in vitamin K arm, 185 in placebo arm). There were no effects of randomisation to vitamin K for radiographic osteoarthritis outcomes. Those with insufficient vitamin K 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 vitamin K on radiographic hand osteoarthritis. SUBJECTS: that were insufficient in vitamin K 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 vitamin K insufficient may be warranted. TRIAL REGISTRATION NUMBER: NCT00183001.