Jeffery LE, et al. - This study was implemented to assess the efficacy of 1,25-dihydroxyvitaminD₃ (1,25(OH)₂D₃) in terms of its anti-inflammatory effects, at the site of active rheumatoid arthritis (RA). As suggested by findings, anti-inflammatory impacts of 1,25(OH)₂D₃ in active RA are impaired due to reduced effects on phenotype-committed, inflammatory memory T cells that are enriched in synovial fluid (SF). As per observations, restoration of 1,25(OH)₂D₃ responses in memory T cells may provide a new strategy for treatment of inflammatory diseases such as RA.