The idea however that issues with vitamin D seemingly present in quite a few cases of ASD  (see here too) but not all  might actually have more direct consequences for behavioural presentation is something which is deserving of quite a bit more experimental study. I'm minded to suggest that the paper by Frighi and colleagues  might also be relevant here given the heightened prevalence of intellectual disability associated with (some) autism.
|"The light that burns twice as |
bright burns half as long"
I'll admit that I have not been able to fully take in all the details of the Jia paper given that it is published in Chinese. But looking at the abstract and using a translation tool for the full-text version ("OK Google, translate..."), a few things were seemingly apparent:
- This is a case report detailing the clinical experiences of a young boy aged 32 months who fitted the DSM-IV criteria for an ASD. Apparently there is some interest in vitamin D and autism at the authors' affiliated institution (see here).
- As part of some biological work-up the young boy was found to present with low levels of vitamin D (serum 25 (OH) D) (14.3 ng/ml). Depending on how you would define adequate vitamin D levels, this value would probably reflect deficiency (see here).
- Treatment of the vitamin D deficiency followed involving an injection of 150,000 IU (international units) of vitamin D3 combined with daily 400 IU of vitamin D3 administered by mouth. The authors note that no other treatment was provided at this time.
- At 2 months, behaviour was reassessed by CARS and M-CHAT among things, and serum 25 (OH) D levels examined again. Vitamin D levels had increased to 51.8 ng/ml which put him within the normal concentration range. Allied to this increase, autistic symptoms were also noted to have improved. The authors suggest that their results warrant further, larger and more controlled, study, something which appears to have already started .
Before anyone gets the idea that I'm advocating vitamin D3 injections for autism or anything else, I would very much like to reiterate the authors' point about needing further research in this area bearing in mind the more typical relationship between vitamin D and something like bone health for example. The recent guidance from the American Academy of Pediatrics (AAP) on optimising bone health in children and adolescents  might also be pertinent. The use of 150,000 IU of vitamin D has also been discussed previously in the more general peer-reviewed literature  particularly if and when compliance to an oral treatment regime might be poor. But that still does not mean that I'm advocating anything at this time.
I'm afraid that I cannot readily offer any specific biological reasons why vitamin D supplementation might tie into the symptom improvements noted in the Jia study given the seemingly wide range of systems showing some involvement for the sunshine vitamin/hormone. I could speculate about certain processes being potentially affected (see here) which might be relevant to cases of autism but won't say too much more about that at this time. This might be a good point to also drop in the paper by Sarah Hanieh and colleagues  (open-access) talking about maternal vitamin D levels and offspring language scores as potentially being pertinent.
I should reiterate that the Jia paper was based on an individual case report so one has to perhaps be slightly weary of any effect being potentially applicable to others nor solely due to vitamin D. This, particularly given the receipt of a diagnosis of ASD at baseline and what this might have meant for things like education and the use of less-formal intervention options over the course of the study period.
That all being said, I continue to find the reported results interesting  if not just from the perspective of autism to more general health and wellbeing...
Classical music to close and since we're not so far from there: remember, remember the 5th of November, the gunpowder treason and plot... (and the world according to 'V').
 Jia F. et al. Vitamin D Supplementation Improves Autistic Symptoms in a Child with Autism
Spectrum Disorder. Asian Case Reports in Pediatrics. 2014; 2: 21-24.
 Pioggia G. et al. Autism and lack of D3 vitamin: A systematic review. Research in Autism Spectrum Disorders. 2014; 8: 1685-1698.
 Uğur C. & Gürkan CK. Serum vitamin D and folate levels in children with autism spectrum disorders. Research in Autism Spectrum Disorders. 2014; 8: 1641-1647.
 Frighi V. et al. Vitamin D deficiency in patients with intellectual disabilities: prevalence, risk factors and management strategies. Br J Psychiatry. 2014 Sep 25. pii: bjp.bp.113.143511.
 Ucuz II. et al. The relationship between Vitamin D, autistic spectrum disorders, and cognitive development: do glial cell line-derived neurotrophic factor and nerve growth factor play a role in this relationship? International Journal of Developmental Disabilities. 2014. DOI: http://dx.doi.org/10.1179/2047387714Y.0000000054
 Golden NH. et al. Optimizing Bone Health in Children and Adolescents. Pediatrics. 29 Sept.
 Munns C. et al. Prevention and treatment of infant and childhood vitamin D deficiency in Australia and New Zealand: a consensus statement. Med J Aust. 2006 Sep 4;185(5):268-72.
 Garland CF. et al. Meta-analysis of all-cause mortality according to serum 25-hydroxyvitamin D. Am J Public Health. 2014 Aug;104(8):e43-50.
 Hanieh S. et al. Maternal vitamin D status and infant outcomes in rural Vietnam: a prospective cohort study. PLoS One. 2014 Jun 26;9(6):e99005.