Approximately 30% to 50% residual β-cell function may remain at the time of type 1 diabetes (T1D) diagnosis, and this may persist for months or years.1,2 A prolonged partial remission (PR) phase of T1D leads to improved glycemic control and decreased long-term complications.1 We previously reported1 that ergocalciferol significantly decreased circulating tumor necrosis factor (TNF)-α and temporal trends in both hemoglobin A1c (HbA1c) and insulin dose–adjusted A1c (IDAA1c), a marker of PR, compared with placebo. Here, TNF is linked to type 1 diabetes mellitus.