Double-blind randomised, placebo-controlled trial of vitamin D in autism

Update 14th May 2019: The paper by Saad et al has been retracted (see here).

It was inevitable ("it is your destiny") that I would formulate a post about the paper published by Khaled Saad and colleagues [1] reporting results based on "a double-blinded, randomized clinical trial (RCT)" looking at the potential usefulness of a vitamin D supplement on "the core symptoms of autism in children." Inevitable because the peer-reviewed research literature looking at the sunshine vitamin/hormone in relation to autism is getting rather voluminous (see here and see here for examples) with the promise of lots more to come (see here). The fact that the name Saad in relation to this area of autism research has appeared before on this blog (see here) indicates that this researcher/research group are no strangers to this area of autism science.

First, thanks to Alex for the Saad paper. And so... utilising the premier research design, where 109 children* (aged 3-10 years old) diagnosed with an autism spectrum disorder (ASD) were randomly allocated to receive vitamin D drops - "300 IU [international units] vitamin D3/kg/day, not to exceed 5,000 IU/day" - or a placebo drops over 4 months and then tested blind "by the Childhood Autism Rating Scale (CARS), Aberrant Behavior Checklist (ABC), Social Responsiveness Scale (SRS), and the Autism Treatment Evaluation Checklist (ATEC)" before and after their vitamin D or placebo, some interesting results emerged. Their trial and protocol, by the way, was also registered. [*Actually, 120 children were initially allocated to vitamin D or placebo but 11 were lost to follow-up or discontinued participation in the study.]

Results: well first and foremost the tenet 'do no harm' seemed to be adhered to as we are told that "vitamin D was well tolerated by the ASD children" at least for the study duration. This is particularly important in light of that case report a few weeks back talking about vitamin D toxicity in the context of autism (see here). Indeed: "The serum levels of 25-hydroxycholecalciferol (25 (OH)D) were measured at the beginning and at the end of the study" kinda shows that authors were probably mindful of possible toxicity issues [2] alongside wanting to get a little more information about baseline vs. endpoint levels of the stuff. Having said all that the use of vitamin D was not completely side-effect free as 5 children taking the vitamin D drops reported symptoms such as "skin rashes, itching, and diarrhea."

Further: "The autism symptoms of the children improved significantly, following 4-month vitamin D3 supplementation, but not in the placebo group." Scores on the CARS (Total scores) showed a "significant decrease" in the vitamin D group compared with the group taking the placebo drops. This was in the direction of vitamin D supplementation positively impacting on the presentation of autistic symptoms. Scores on the ATEC also showed something akin to improvement for those taking the vitamin D drops. As one might expect, measured levels of vitamin D - "serum levels of 25 (OH)D" - rose in the vitamin D supplemented group compared to those in the placebo group.

These are interesting results providing some of the first double-blind RCT findings in relation to vitamin D supplementation and autism. I particularly like the fact that alongside well-validated instruments such as the CARS for 'measuring autism', the authors also included the ATEC, an instrument that I have growing fondness for (see here). They also measured functional vitamin D levels (albeit via an ELISA assay - I'd prefer via mass spec!) so it's not difficult to see that minus any unknown variables, the behavioural changes seem to match the biological changes to vitamin D status.

There is more to do and indeed, more research in this area is already underway. Larger groups of participants still following that gold standard research methodology will give a more accurate picture and perhaps provide some details about potential best responders to such an intervention (something already hinted at in the Saad data). And then there is the question of 'how' vitamin D might be affecting the presentation of [some] autism. Well, far be it from me to speculate too much, and also taking into account what Saad et al have to say on this matter, I suggest that we might learn a thing or two from looking at vitamin D use in other areas of medicine (see here) and taking things from there...

For now, here is what the UK Government says about vitamin D and the population at large although not everyone is convinced...

Music: Kate Bush and This Woman's Work....

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[1] Saad K. et al. Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder. J Child Psychol Psychiatry. 2016 Nov 21.

[2] Vogiatzi MG. et al. Vitamin D supplementation and risk of toxicity in pediatrics: a review of current literature. J Clin Endocrinol Metab. 2014 Apr;99(4):1132-41.

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Saad K, Abdel-Rahman AA, Elserogy YM, Al-Atram AA, El-Houfey AA, Othman HA, Bjørklund G, Jia F, Urbina MA, Abo-Elela MG, Ahmad FA, Abd El-Baseer KA, Ahmed AE, & Abdel-Salam AM (2016). Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder. Journal of child psychology and psychiatry, and allied disciplines PMID: 27868194