25-hydroxyvitamin D Level in Autism Spectrum Disorders and the Efficacy of Vitamin D Supplementation in Saudi Autistic Children

Background: Autism spectrum disorder (ASD) is a frequent developmental disease characterized by defects in nonverbal and verbal communication, pervasive deficits in social interaction, and stereotyped patterns of activities and interests. Previous researches reported vitamin D deficiency in autistic children; however, there is a deficiency of vitamin D supplementation trials in ASD children. This study aimed to assess vitamin D levels in ASD children and the effects of vitamin D supplementation on behavior and ASD score severity.

Methods: Eleven Saudi autistic children (9 males and 2 females) with ages ranged from 4 to 12 years were included in this prospective study during the period from January to July 2022. Children with ASD obtained from Will Be center for Special Needs and The Leading Academy for Autism. The study was carried out in two stages. In the first stage, 25-hydroxyvitamin D serum levels and autism severity via Gilliam Autism Rating Scale (GARS) were estimated. Then participants who fulfilled the inclusion criteria (9 out of 11) were included and given vitamin D supplements for three months. During treatment, ASD child behavior was observed. For the second stage, after treatment, changes in vitamin D level and autism score severity were evaluated.

Results: A total of 11 autistic children participated; two of them had vitamin D levels that were > 80 nmol/L excluded. Out of 9 ASD included 5 cases had deficiency and 4 cases had severe deficiency of vitamin D (55.56% and 44.44%). Before treatment, ASD severities were above average (n=1, 11.11%), average (n=6, 66.67%), and low severity (n=3, 33.33%). After 3 months of vitamin D treatment, vitamin D serum levels were sufficient in 2 patients (22.22%) and insufficient in 7 cases (77.78%). Meanwhile, ASD severity had no clear improvement following vitamin D supplementation with 7 (77.78%) cases showed average severity and 2 (22.22%) cases with low severity. Nevertheless, the specialist clarified that there was an enhancement in some behaviors and responses for most patients. After treatment, there was a significance increased in 25-hydroxyvitamin D serum levels and a decrease in ASD severity compared to its level before treatment.

Conclusions: Vitamin D levels are insufficient in 82% of ASD children (9 out of 11). Of 9 ASD patients; vitamin D levels were deficiency and severe deficiency and ASD severities were average and low severity. After treatment, vitamin D level was sufficient only in 2 patients (22.22%) and only one ASD case had improved in ASD score (Average to low). Nevertheless, specialist reported enhancement in some behaviors and responses for most patients. Nutritional interventions with vitamin D make a little difference in autistic children's life by reducing their symptoms.