Review of Research Paper
Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder
Khaled Saad et al.
Journal of Child Psychology and Psychiatry
Autism Spectrum Disorder (ASD), typically just called Autism, is a wide range of developmental disorders such as social difficulties, repetitive behaviors, and other symptoms that could hurt one’s ability to function socially at school, at work, in everyday life. Some people are mildly impaired, while others are severely disabled and will require care their whole life. Rates of autism have increased exponentially. According to the most recent data from the CDC, ASD is reported in 1 of 68 children (1 in 42 boys) – this is a rise from 1 in 150 children in 2002 and 1 in 110 in 2006 (source: Centers for Disease Control).
Could vitamin D deficiency be part of the problem? Vitamin D has only been tracked by the government since the early 2000s, so we don’t know what the rates were before, but recent data (NHANES 2009-2010) shows that about 91% of children are under the recommended 40 ng/ml (100 nmol/L) and 41% of African American children are below 20 ng/ml (50 nmol/L).
Randomized controlled trial
A randomized controlled trial was run in Egypt, by Khaled Saad et al., which tested 109 children with autism (85 boys, 24 girls), ages 3-10. The treatment group received 300 IU vitamin D daily per kilogram of body weight (maximum of 5000 IU/day) of vitamin D3 drops (liquid) and the placebo group received a matching bottle with no vitamin D in the suspension. The study was conducted over 4 months.
Serum vitamin D levels were measured at the beginning and end of the study. ASD symptoms were assessed by the Childhood Autism Rating Scale (CARS), Aberrant Behavior Checklist (ABC), Social Responsiveness Scale (SRS), and the Autism Treatment Evaluation Checklist (ATEC).
At the start of the study, there was no significant difference in CARS scores between the two groups. After 4 months of intervention, the CARS scores in the treatment group were significantly improved compared to the placebo group. CARS scores, which are defined on a scale of 15-60, reflect the level of autistic behaviors. Less than 30 is considered non-autistic, 30-37 is mild autism, and greater than 37 is severely autistic.
At the start of the study, the vitamin D group had a mean CARS score of 36.8 and a mean vitamin D level of 26.3 ng/ml (65.6 nmol/L). Over the 4 months, their vitamin D levels increased to a mean of 45.9 ng/ml (114.6 nmol/L) and the mean CARS score decreased to 30.3 – that is almost non-autistic!
The placebo group remained level – a mean vitamin D level of 27.1 ng/ml (67.6 nmol/L) and 28.2 ng/ml (70.4 nmol/L) at the beginning and end, respectively. CARS scores started with a mean of 37.1 and ended with a mean of 36.4.
No children who measured as vitamin D deficient (< 20 ng/ml) were included in the study, instead, the study authors provided vitamin D to those patients.
There were few adverse effects in the vitamin D group. Side effects were reported in 5 patients and included skin rashes, itching, and diarrhea; all side effects were mild and transient.
Significant Change in Nutrient Status
There are five criteria, also known as the Heaney Criteria, of a good nutrient study. One of these is to create a big enough change in the nutrient status (in this case from an average of 27 ng/ml to 45 ng/ml). This nutrient change was most likely due to the fact that they used young children. Their supplementation goal was 300 IU/day for every kilogram of body weight but was capped at 5000 IU/day. This corresponds to about 36 lbs of body weight. The average weight for the children in the study was about 45 lbs, so they almost achieved their desired dosing. If we were to apply this dosing goal and cap to an adult audience, the 300 IU per kilogram would amount to 20,000 IU/day for an average weight adult (150 lbs), and so capping at 5,000 IU would most likely not show a significant change in nutrient status.
The important point is that this study found a significant change in nutrient status in the treatment group, so the researchers were able to make a determination on whether or not vitamin D improved their condition (it did!).
While it is commendable for the study authors to not accept deficient children, and instead to start them on a supplementation regimen, as you can see from the NHANES charts above – many children are deficient right now. We can only guess, but if all children were included we might have seen an even bigger decrease in CARS scores (improvement), as the nutrient level would have seen an even bigger change.