Title

The Effects of Vitamin D and Marine Omega-3 Fatty Acid Supplementation on Chronic Knee Pain in Older U.S. Adults: Results From a Randomized Trial

Document Type

Peer-Reviewed Article

Publication Date

2020

Program

Physical Therapy

Abstract

Objective: Knee pain from osteoarthritis is frequent in the adult population. Prior trials have had conflicting results concerning vitamin D's therapeutic effects on knee pain and few trials have investigated marine omega-3 fatty acids (n-3 FA). Methods: The double-blind, placebo-controlled VITamin D and OmegA-3 TriaL (VITAL) randomized 25,871 U.S. adults in a two-by-two factorial design to vitamin D and n-3 FA. We identified a subgroup with chronic knee pain prior to randomization and assessed knee pain at baseline and annually during follow-up with the Western Ontario and McMaster Universities Arthritis Index (WOMAC; 0-100, 100 worst). Repeated measures modeling tested the effect of randomized treatment on WOMAC Pain over follow-up after adjustment for age and sex. Analyses were repeated for WOMAC Function and Stiffness. Results: We included 1,398 participants who returned at least one knee pain questionnaire. Mean age was 67.7 years, 66% were female, and mean WOMAC Pain was 37 (SD 19). Mean follow-up time was 5.3 years (SD 0.7). WOMAC Pain did not differ between vitamin D or n-3 FA and placebo at any time point during follow-up. Linear time by treatment interactions were not statistically significant for either treatment (vitamin D p= 0.41, n-3 FA p= 0.77). Vitamin D and n-3 FA supplementation did not significantly affect WOMAC Function or Stiffness scores over time. Conclusion: Vitamin D and n-3 FA supplementation for a mean of 5.3 years did not reduce knee pain or improve function or stiffness in a large sample of U.S adults with chronic knee pain.

Comments

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. This version will be made available on this site after a 12 month embargo.

DOI

10.1002/art.41416

PMID

32583982

Publication

Arthritis & Rheumatology

Publisher

Wiley


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