Vitamin D3 & Autism: Does Supplementation Improve Symptoms?

by Ashley Jordan Ferira, PhD, RDN

Autism spectrum disorder (ASD) is a complex neurodevelopmental syndrome with significant social, communication and behavioral deficits and challenges.¹ No cure exists for ASD, although early interventions (birth to 3 years) can yield developmental improvements.¹ ASD impacts approximately 1 in 68 children in the US and is 4.5 times more common in boys (1 in 42) than girls (1 in 189).²

Vitamin D’s extraskeletal roles are numerous, including its role as a neurosteroid, impacting both brain development and connectivity, and likely synaptic plasticity as well.³ Vitamin D is also one of the most common micronutrient deficiencies. Previous research has revealed associations between gestational and early childhood vitamin D insufficiency and ASD.⁴ This suggests that hypovitaminosis D represents a modifiable risk factor for ASD.⁴ Furthermore, preliminary evidence demonstrates that gene variants related to vitamin D metabolism play a role in the pathophysiology of ASD.⁵ Robustly designed intervention trials have been scant.

The first double-blind randomized controlled trial (RCT) utilizing vitamin D₃ supplementation in children with ASD was published in The Journal of Child Psychology and Psychiatry in 2018.⁶ The study included 109 Egyptian children (85 boys; 24 girls) 3-10 years of age with confirmed ASD diagnosis. The children were randomized to receive vitamin D₃ drops (300 IU D₃/kg/day; not to exceed 5,000 IU/day) or matching placebo drops daily for 4 months.⁶ Serum 25-hydroxyvitamin D (25[OH]D) levels were measured at baseline and 4-months. For ethical reasons, children who were identified to have vitamin D deficiency (25[OH]D <20ng/mL) were excluded from the study and administered vitamin D supplementation by the study authors.⁶ Autism symptoms were assessed using validated measures completed by two different psychologists and a senior psychiatrist.⁶

Four months of daily vitamin D₃ supplementation at 300 IU/kg/day:⁶

• Significantly increased average 25(OH)D levels, from 26.3 ng/mL at baseline to 45.9 ng/mL at 4 months
• Was well-tolerated, with no observed aberrations in pertinent biochemical markers (e.g. calcium, liver enzymes, creatinine, BUN, etc.)

Following 4 months of vitamin D₃ supplementation, improvements (all p <0.05, most p <0.01; as compared to placebo) were demonstrated in many core manifestations of ASD, including:⁶

• Total Childhood Autism Rating Scale (CARS) score
• Aberrant Behavior Checklist (ABC): irritability, hyperactivity, lethargy/social withdrawal, inappropriate speech, stereotypic behavior
• Autism Treatment Evaluation Checklist (ATEC): sociability, cognitive awareness, behavior
• Social Responsiveness Scale (SRS): total & social awareness, social cognition and autistic mannerism

This rigorously designed RCT is the first of its kind to demonstrate safety and efficacy of vitamin D₃ supplementation in children with ASD.⁶ Two previous open-label vitamin D₃ supplementation studies also demonstrated improvements in ASD symptoms.^7-8 Wide-scale studies are warranted to continue to critically ascertain the effects of vitamin D on ASD.

Why is this Clinically Relevant?

• ASD prevalence has risen over the past few decades, and no cure exists²
• Vitamin D insufficiency is common in pediatric and adult patients
• Associational and intervention trials demonstrate that vitamin D plays a role in ASD
• Clinicians should help women of childbearing age, pregnant and lactating mothers, and children (from birth onward) achieve vitamin D sufficiency through daily vitamin D₃ supplementation, as this important micronutrient potentially represents “low-hanging fruit” in the fight against ASD incidence and development

Link to Article

Citations

1. CDC. Autism Spectrum Disorder. Facts about ASD. https://www.cdc.gov/ncbddd/autism/facts.html. Accessed April 13, 2018.
2. CDC. Autism Spectrum Disorder. Data & Statistics. https://www.cdc.gov/ncbddd/autism/data.html. Accessed April 13, 2018.
3. Cannell JJ. Vitamin D and autism, what’s new? Rev Endocr Metab Disord. 2017;18(2):183-193.
4. Wang T et al. Serum concentration of 25-hydroxyvitamin D in autism spectrum disorder: a systematic review and meta-analysis. Eur Child Adolesc Psychiatry. 2016;25(4):341-350.
5. Schmidt RJ et al. Selected vitamin D metabolic gene variants and risk for autism spectrum disorder in the CHARGE Study. Early Hum Dev. 2015;91(8):483-489.
6. Saad K et al. Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder. J Child Psychol Psychiatry. 2018;59(1):20-29.
7. Saad K et al. Vitamin D status in autism spectrum disorders and the efficacy of vitamin D supplementation in autistic children. Nutr Neurosci. 2016;19(8):346-351.
8. Feng J et al. Clinical improvement following vitamin D3 supplementation in autism spectrum disorder. Nutr Neurosci. 2017;20(5):284-290.