Vitamin D Deficiency's Role In Autism
Do children with common rickets show signs of autism?
If vitamin D deficiency caused autism, then children with vitamin D-deficient rickets would be at greater risk for the disease. To the best of my knowledge, no studies have looked at the psychiatric profiles of children with vitamin D deficient rickets to look for evidence of autism. However, children with rickets are more likely to be hypotonic (flabby muscle tone), display decreased activity, and have developmental motor delays. Hypotonia is common in children with autism, as is decreased activity, and developmental motor delays are the rule. Pettifor JM. Vitamin D deficiency and nutritional rickets in children. Unpublished manuscript. Ming X, Brimacombe M, Wagner GC. Prevalence of motor impairment in autism spectrum disorders. Brain Dev. 2007 Apr 27. Zwaigenbaum L, et al. Behavioral manifestations of autism in the first year of life. Int J Dev Neurosci. 2005 Apr–May;23(2–3):143–52. Provost B, Lopez BR, Heimerl S. A comparison of motor delays in young children: autism spectrum disorder, developmental delay, and developmental concerns. J Autism Dev Disord. 2007 Feb;37(2):321–8.
Vitamin D deficiency in childhood is associated with an increased risk of infections so the vitamin D theory of autism predicts autistic children would be more prone to infections. A recent study found that children who went on to develop autism were not prone to increased infection in the first 2 years of their life but they looked at infection rates before the child was diagnosed with autism, not afterwards. Three earlier studies found an increased incidence of infections in children with autism. A Japanese study found a very strong positive correlation between the prevalence of infantile autism in 1-year birth cohorts (groups) and the total number of children hospitalized for pneumonia and bronchiolitis during that cohort's birth year. Wayse V, Yousafzai A, Mogale K, Filteau S. Association of subclinical vitamin D deficiency with severe acute lower respiratory infection in Indian children under 5 y. Eur J Clin Nutr. 2004 Apr;58(4):563–7. Rosen NJ, Yoshida CK, Croen LA. Infection in the first 2 years of life and autism spectrum disorders. Pediatrics. 2007 Jan;119(1):e61–9. Konstantareas MM, Homatidis S. Ear infections in autistic and normal children. J Autism Dev Disord. 1987 Dec;17(4):585–94. Rosenhall U, et al. Autism and hearing loss. J Autism Dev Disord. 1999 Oct;29(5):349–57. Deykin EY, MacMahon B. Viral exposure and autism. Am J Epidemiol. 1979 Jun;109(6):628–38. Tanoue Y, Oda S, Asano F, Kawashima K. Epidemiology of infantile autism in southern Ibaraki, Japan: differences in prevalence in birth cohorts. J Autism Dev Disord. 1988 Jun;18(2):155–66.
The vitamin D theory predicts medications that lower vitamin D levels, if taken during pregnancy, would increase the risk for autism. While little is known about the drugs that interfere with vitamin D metabolism, sodium valproate (Depakote) is one drug that lowers vitamin D levels and the drug has been associated with autism. Nicolaidou P, et al. Effects of anticonvulsant therapy on vitamin D status in children: prospective monitoring study. J Child Neurol. 2006 Mar;21(3):205–9. Rasalam AD, et al. Characteristics of fetal anticonvulsant syndrome associated autistic disorder. Dev Med Child Neurol. 2005 Aug;47(8):551–5.
Seizures are very common in autism and activated vitamin D increases the seizure threshold, making brain tissue less likely to seize. A controlled study found vitamin D reduced the incidence of seizures in patients with intractable seizures. Rossi PG, et al. EEG features and epilepsy in patients with autism. Brain Dev. 1995 May–Jun;17(3):169–74. Siegel A, et al. Administration of 1,25-dihydroxyvitamin D3 results in the elevation of hippocampal seizure threshold levels in rats. Brain Res. 1984 Apr 23;298(1):125–9. Christiansen C, Rodbro P, Sjo O. "Anticonvulsant action" of vitamin D in epileptic patients? A controlled pilot study. Br Med J. 1974 May 4;2(5913):258–9.» page: autism index 1 2 3 4 5 6 7 8 9 10 11