Doi Y, Tsujita M, Hamano T, et al. - Researchers aimed at ascertaining the effect of cholecalciferol supplementation on allograft outcomes in kidney transplant recipients (KTRs). In this single‐center randomized, double‐blind, placebo‐controlled trial, KTRs received daily 4000‐IU cholecalciferol supplementation at 1‐month posttransplant. A total of 193 patients were randomized, 180 participants completed the study. In subgroup analyses, patients with eGFR < 45 mL/min/1.73m ² exhibited detrimental effects of cholecalciferol. The groups did not differ in the degree of interstitial fibrosis and tubular atrophy (IFTA), changes in urine albumin‐to‐creatinine ratio, or adverse events including hypercalcemia and infections requiring hospitalization. Overall findings suggest no influence of cholecalciferol supplementation on eGFR change compared with placebo among incident KTRs. Hence, cholecalciferol supplementation is not supported for improving allograft function in incident KTRs.