Study of autism and vitamin D earns retraction after questions about reliability

Marco Vertch

A pediatrics journal has retracted a 2016 article purporting to be the first randomized controlled trial on the effects of vitamin D supplements on autism over concerns about the reliability of the findings.

The paper, “Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder,” appeared in the Journal of Child Psychology and Psychiatry and has been cited 27 times, according to Clarivate Analytics’ Web of Science, earning it a “highly cited paper” designation compared to its counterparts of a similar age.

The authors came from Egypt, Saudi Arabia, China, Chile, the UK and Norway. According to the abstract, the researchers looked at the effects of vitamin D supplements on 109 boys and girls with autism:

The autism symptoms of the children improved significantly, following 4‐month vitamin D3 supplementation, but not in the placebo group. This study demonstrates the efficacy and tolerability of high doses of vitamin D3 in children with ASD.

This study is the first double‐blinded RCT proving the efficacy of vitamin D3 in ASD patients. Depending on the parameters measured in the study, oral vitamin D supplementation may safely improve signs and symptoms of ASD and could be recommended for children with ASD. At this stage, this study is a single RCT with a small number of patients, and a great deal of additional wide‐scale studies are needed to critically validate the efficacy of vitamin D in ASD.

But readers questioned the findings, prompting the editors to ask the authors for their data — which they couldn’t provide:

The above article, published in print in the Jan 2018 issue of the Journal of Child Psychology & Psychiatry and online in Wiley Online Library (, has been retracted by the JCPP Editor‐in‐Chief, Edmund Sonuga‐Barke, and John Wiley & Sons.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 [links added here by RW]), 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.

We emailed the corresponding author for comment but didn’t hear back.

The notion that low levels of vitamin D might be linked to autism has been bouncing around for more than a decade.  

Hat tip: Rolf Degen

Like Retraction Watch? You can make a tax-deductible contribution to support our growth, follow us on Twitter, like us on Facebook, add us to your RSS reader, sign up for an email every time there’s a new post (look for the “follow” button at the lower right part of your screen), or subscribe to our daily digest. If you find a retraction that’s not in our database, you can let us know here. For comments or feedback, email us at

4 thoughts on “Study of autism and vitamin D earns retraction after questions about reliability”

  1. I believe autism is a complex disease. Retraction of paper outcomes is not a big deal, because science makes advancemend based on error, to some extent. I am a doctor working in antibody production, so I know how hard it is to publish a significant research paper.

    1. Yes, failing is a crucial step in the scientific process (and any road to success for that matter), yet it remains important to retract when appropriate and to insist upon verification–otherwise it’s a faith-based endeavor and not something I’m going to invest my time and hope in.

    2. Finding out you were wrong is how science works, no big deal. Someone else finding out your results were fake or the work so sloppy as to come to the wrong conclusion is a very big deal. This could lead to mistreatment of patients amongst a host of other problems. Its deeply worrying a doctor thinks this is no big deal.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.