The authors of this study evaluated differences in T helper cell subtypes osteoclast precursors in peripheral blood between patients affected by early rheumatoid arthritis (eRA) and healthy controls.[1] They evaluated the effects of vitamin D through a parallel, randomized double blind, placebo-controlled trial. Patients treated with glucocorticoids (GCs), disease modifying activity drugs, and biologic agents within the past 6 months were also excluded. The results showed that in eRA, 25OH vitamin D levels were significantly lower. After 3 months, the combined use of vitamin D significantly improved the effect of treatment on global health. In eRA, a significant imbalance in T CD4+ subtypes, accompanied by increased levels of non-classical OCs precursors and pro-inflammatory cytokines, was observed. The authors conclude that a single dose of vitamin D (300,000 IU) combined with standard treatment significantly improve patients general health.