Vitamin D Receptor Polymorphisms Associated with Autism Spectrum Disorder.
A common vitamin D receptor gene variant is tied to higher autism severity, so checking vitamin D status may guide simple, low-risk support.
01Research in Context
What this study did
Guerini et al. (2020) looked at vitamin D receptor genes in Italian children with autism and their healthy brothers or sisters.
They checked which version of the VDR FokI gene each child carried and compared it to autism severity scores.
What they found
Kids with the VDR FokI (T) allele had higher CARS scores and more hyperactivity.
The protective (C) allele and a CCAG gene pattern showed up more often in the healthy siblings.
How this fits with other research
Two studies seem to clash with Rosa. Green et al. (2020) found no link between moms’ vitamin D in pregnancy and later ASD in a U.S. cohort. Ali et al. (2019) also saw no connection between preschool vitamin D levels and autism diagnosis.
The gap is simple: Rosa tested genes, the others tested blood levels. Genes stay the same for life, while blood levels change daily.
de Wit et al. (2024) backs Rosa up by showing young adults with ASD have much lower vitamin D in their blood, hinting the vitamin D pathway keeps mattering after childhood.
Why it matters
If a child carries the VDR FokI (T) allele, low vitamin D could worsen autism traits. You can’t change genes, but you can check vitamin D status with a quick blood test. If it’s low, a pediatrician-approved supplement might help reduce hyperactivity and raise learning readiness. Track behavior for two weeks after starting any vitamin D plan to see if it helps that child.
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02At a glance
03Original abstract
Vitamin D is endowed with a number of biological properties, including down-regulation of inflammation, and might contribute to the pathogenesis of autism spectrum disorders (ASD). Vitamin D binds to the vitamin D Receptor (VDR); the biological activity of the ensuing complex depends on VDR FokI, BsmI, ApaI, and TaqI gene polymorphisms. We evaluated such Single Nucletoide Polymorphismsm (SNPs) in a cohort of 100 Italian families with ASD children. FokI genotype distribution was skewed in ASD children compared with their healthy sibs (Pc = 0.03 2 df) and to a group of 170 Italian healthy women (HC) (Pc = 0.04 2 df). FokI genotype and allelic distribution skewing were also observed in mothers of ASD children compared to HC (Pc = 0.04 2 df). Both Transmission Disequilibrium Test for single loci and haplotype analysis distribution revealed a major FokI (C) allele-mediated protective effect, which was more frequently transmitted (73%) than not transmitted to healthy sibs (P = 0.02). A protective FokI-, BsmI-, ApaI-, and TaqI (CCAG) haplotype was more frequently carried by healthy sibs than by ASD children (P = 1 × 10-4 ; OR: 0.1, 95% CI: 0.03-0.4) too. Finally, a strong gene-dose association of FokI (T) allele with both higher Childhood Autism Rating Scale score (Pc = 0.01) and, particularly, with hyperactivity behavior (Pc = 0.006) emerged in ASD children. Because the protein produced by the FokI (T) allele is transcriptionally less active than that produced by the FokI (C) allele, the reduced biological activity of the vitamin D/VDR complex prevalent in ASD could favor ASD- and maternal immune activation- associated inflammation. Vitamin D supplementation might be useful in preventative and rehabilitation protocols for ASD. Autism Res 2020, 13: 680-690. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Vitamin D deficiency and Vitamin D receptor (VDR) polymorphisms are associated with structural and functional brain abnormalities and behavioral disorders. We analyzed the association of VDR gene polymorphisms in a cohort of 100 Italian families with ASD children. A strong correlation between one of the VDR polymorphisms and hyperactivity behavior was evidenced in ASD children. In healthy mothers, the same VDR polymorphism was also correlated with an increased risk of giving birth to children with ASD.
Autism research : official journal of the International Society for Autism Research, 2020 · doi:10.1002/aur.2279