Objective: To determine whether there is a correlation between vitamin D levels and palindromic rheumatism (PR) as an at-risk phenotype of rheumatoid arthritis (RA).

Methods: A total of 308 participants were enrolled in this cross-sectional study. We recorded their clinical characteristics and performed propensity-score matching (PSM). Serum 25(OH)D3 levels were determined via enzyme-linked immunosorbent assay.

Results: Our PSM resulted in 48 patients with PR and 96 matched control individuals. The multivariate regression analysis we performed after the PSM did not show a significant increase in PR risk in patients with vitamin D deficiency/insufficiency. There was no significant correlation between levels of 25(OH)D3 and frequency/duration of attacks, number of joints affected, and duration of symptoms before diagnosis (P ≥ .05). Mean (SD) serum levels of 25(OH)D3 in patients with and without progression to RA were 28.7 (15.9) ng/mL and 25.1 (11.4) ng/mL, respectively.

Conclusions: Based on the results, we found no clear association between vitamin D serum levels and the risk, severity, and rate of PR progressing into RA.