Retraction: Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder.

The above article, published in print in the Jan 2018 issue of the Journal of Child Psychology & Psychiatry and online in Wiley Online Library (wileyonlinelibrary.com), has been retracted by the JCPP Editor‐in‐Chief, Edmund Sonuga‐Barke, and John Wiley & Sons. Following a series of communications from readers highlighting concerns about the paper (now published on the journal website), the journal editors requested that the authors send them the raw data from the trial. In response the authors informed the editors that; (i) the electronic data base had been lost following a computer outage and (ii) that they could send only 95 out of 120 hard‐copy participant data sheets as one site had closed and was no longer contactable. The substantial data loss in and of itself posed a serious difficulty in verifying the correctness of the data presented in the paper. The JCPP then analysed the data from the 95 cases itself. A number of significant discrepancies emerged between the re‐analysis and the findings reported in the paper both in terms of means and standard deviations of key outcome variables across the trial. These involved very substantial differences that we judged to be extremely unlikely to have arisen due to variations in composition of the original and re‐analysed samples. We also discovered previously unidentified/reported problems with missing data and recording irregularities regarding changes in treatment regimen and subject identifiers. As a result of these issues the Editors no longer have confidence in the findings reported in the original paper. Based on all these matters combined and following published guidance from the Committee on Publishing Ethics (COPE) and Wiley's Best Practice Guidelines on Publishing Ethics, we have decided that the only course of action available to us is to retract the paper. [ABSTRACT FROM AUTHOR]