Food and Behaviour Research

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22 November 2016 - Nutraingredients - Vitamin D3 supplements shown to significantly improve autism symptoms

Annie Harrison-Dunn


Substantial evidence now points to a relative lack of Vitamin D as a risk factor for autism and related neurodevelopmental disorders, especially in early life.

However, this study provides what has been lacking until now - which is evidence from randomized controlled clinical trials that supplementation with Vitamin D can help to reduce symptoms of autistic sprectrum disorders in children with this condition.

As the authors emphasise, confirmation studies are still needed. It is also important to recognise that 'autism spectrum disorder' (like all developmental disorders) is not a unitary condition, and no intervention will help all individuals with that label. Nonetheless, these findings support the case for better monitoring of Vitamin D status - and supplementation to remedy overt deficiencies - in ASD and related behaviour and learning problems.

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Taking vitamin D3 supplements may help improve autism symptoms of children, a first-of-its-kind study has suggested.

The study published in the Journal of Child Psychology and Psychiatry showed symptoms “improved significantly” following four months of vitamin D3 supplements.

This effect was not seen in the placebo group.

The study involving a total of 109 children in Egypt aged 3-10 years is said to be the first double-blinded randomised clinical trial proving the efficacy of vitamin D3 in autism spectrum disorder (ASD) patients.

Researchers from the Assiut University in Egypt said the findings could justify new recommendations for children with the condition.

However they warned: “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.

What is autism spectrum disorder?

Autism spectrum disorder (ASD), which can include forms like Asperger syndrome, is a condition that affects social interaction, communication, interests and behaviour.

Symptoms usually present themselves by the time a child is three years old, and can include difficulty with eye contact and body language and deviations from routine often triggering  tantrums.

It's thought one in every 100 people in the UK has ASD, with boys more likely to be diagnosed than girls.

Carol Povey, director of the Centre for Autism at the National Autistic Society in the UK, echoed this saying it was “too early” to draw any firm conclusions from the study.

“It is important to remember that autism is a lifelong disability - children who are autistic will become autistic adults - and the most crucial thing is that every autistic person has the right support to meet their needs,” she told us.  

“We urge that parents and autistic people do not base any decisions on this research until further studies are carried out.

“However, if reproducible large scale research can confirm this finding, it is possible that Vitamin D, alongside the right support, could help improve the lives of the 140,000 children on the autism spectrum in the UK.” 

Mounting evidence

There is no ‘cure’ for autism, instead it is managed though education, supportive care, and behavioural strategies.

However this paper follows previous findings suggesting an association between the risk of ASD and low vitamin D levels.

Data published last year showed 57% of children with ASD had vitamin D deficiency, and another 30% of them had vitamin D ‘insufficiency’ and these levels were also linked with the severity of autism.

Maternal vitamin D deficiency during pregnancy and/or early childhood has also been put forward as a possible risk factor in the development of the condition.

The daily D dose

The daily doses in this latest study were worked out at 300 international units (IU) of vitamin D3 per kg of the children’s body weight and never exceeded 5,000 IU per day.

This year the European Food Safety Authority (EFSA) set an adequate intake (AI) level of 15 micrograms (600 IU) per day from food sources for adults and children.

The opinion built on from its 2012 recommendation that children aged 11-17 years should not exceed Tolerable Upper Intake Levels (ULs) of 100 µg per day (4,000 IU) while younger children should not exceed 50 µg/day (2,000 IU).

The researchers said the realitively high rates of vitamin D3 given to the children were “well tolerated”.

They said side effects such as skin rashes, itching and diarrhea were reported in five (8.3%) of the children.

Yet they said these side effects were mild and brief and only three patients discontinued the vitamin D treatment.

Measuring changes

The autism severity and social maturity of the children were assessed using the Childhood Autism Rating Scale (CARS), Aberrant Behavior Checklist (ABC), Social Responsiveness Scale (SRS) and the Autism Treatment Evaluation Checklist (ATEC). 

These scores tracked symptoms like irritability, hyperactivity, social withdrawal and inappropriate speech.

CARS scores improved by a 4–10 point drop in 42 (76.4%) of the children given vitamin D,  while another 10 (18.2%) had a 1-3-point improvement. Only three (5.4%) children showed no improvements.

The paper was penned by researchers from eight different institutions: Assiut University, Aswan University, South Valley University and Alazhar University in Egypt, Almajmaah University in Saudi Arabia, the Council for Nutritional and Environmental Medicine in Norway, the First Hospital of Jilin in China and the University of Exeter in England.