Cannell pointed out that children with Williams syndrome1, who have greatly elevated 1,25-dihydroxyvitamin D levels in early infancy2 often have characteristics opposite to those of autism: remarkable sociability, overfriendliness, empathy, and willingness to initiate social interaction3.
Additional evidence for a role of vitamin D in explaining the prevalence and symptoms of autism have appeared since Cannell’s hypothesis was first proposed4. For example, subsequent studies provided more evidence that dark skin is a risk factor for development of autism56.
A recent paper examined the presence of autism according to maternal immigrant status and ethnic origin7. Four papers8 91011 regarding maternal foreign birth and three papers regarding maternal ethnic origin8 1213 were reviewed. All four foreign birth studies found significantly increased risk of autism for some of the countries. Most of the maternal ethnic origin studies found significantly increased risk of autism for black vs. white mothers. Two studies did not find significant risk of autism related to paternal immigrant status10 or ethnic origin13. It was also noted that the association between autism and maternal 25(OH)D levels is similar to that for schizophrenia14 15. This review provides strong support for the UVB-vitamin D-autism hypothesis.
Two papers reported differences in bone development for those with autism: one regarding metacarpal bone thickness16, the other involving second and fourth finger digit lengths17. Since a primary role of vitamin D is control of calcium absorption and metabolism, these two studies provide indirect evidence for a role of vitamin D deficiency in the etiology of autism.
“Compared with infants born at term, the unadjusted ORs for autistic disorders among very and moderately preterm infants were 2.05 [95% CI: 1.26-3.34] and 1.55 [95% CI: 1.22-1.96], respectively.”18. Low maternal serum 25(OH)D levels are a risk factor for premature delivery19. However, there are other risk factors for preterm delivery.
While these and other findings do not prove that vitamin D reduces the risk of autism, the theory is strong enough that it “deserves immediate attempts to disprove it”24.
Page last edited: 17 May 2011
- Kaplan, P. Wang, P. P. Francke, U. Williams (Williams Beuren) syndrome: a distinct neurobehavioral disorder. J Child Neurol. 2001 Mar; 16 (3): 177-90.
- Garabedian, M. Jacqz, E. Guillozo, H. Grimberg, R. Guillot, M. Gagnadoux, M. F. Broyer, M. Lenoir, G. Balsan, S. Elevated plasma 1,25-dihydroxyvitamin D concentrations in infants with hypercalcemia and an elfin facies. N Engl J Med. 1985 Apr 11; 312 (15): 948-52.
- Mervis, C. B. Klein-Tasman, B. P. Williams syndrome: cognition, personality, and adaptive behavior. Ment Retard Dev Disabil Res Rev. 2000; 6 (2): 148-58.
- Cannell, J. J. Autism and vitamin D. The Vitamin D Newsletter. 2007 May;
- Bejerot, S. Humble, M. [Increased occurrence of autism among Somali children–does vitamin D deficiency play a role?]. Tidsskr Nor Laegeforen. 2008 Sep 11; 128 (17): 1986-7.
- Fernell, E. Barnevik-Olsson, M. Bagenholm, G. Gillberg, C. Gustafsson, S. Saaf, M. Serum levels of 25-hydroxyvitamin D in mothers of Swedish and of Somali origin who have children with and without autism. Acta Paediatr. 2010 May; 99 (5): 743-7.
- Dealberto, M. J. Prevalence of autism according to maternal immigrant status and ethnic origin. Acta Psychiatr Scand. 2011 May; 123 (5): 339-48.
- Croen, L. A. Grether, J. K. Selvin, S. Descriptive epidemiology of autism in a California population: who is at risk?. J Autism Dev Disord. 2002 Jun; 32 (3): 217-24.
- Hultman, C. M. Sparen, P. Cnattingius, S. Perinatal risk factors for infantile autism. Epidemiology. 2002 Jul; 13 (4): 417-23.
- Lauritsen, M. B. Pedersen, C. B. Mortensen, P. B. Effects of familial risk factors and place of birth on the risk of autism: a nationwide register-based study. J Child Psychol Psychiatry. 2005 Sep; 46 (9): 963-71.
- Williams, K. Helmer, M. Duncan, G. W. Peat, J. K. Mellis, C. M. Perinatal and maternal risk factors for autism spectrum disorders in New South Wales, Australia. Child Care Health Dev. 2008 Mar; 34 (2): 249-56.
- Bhasin, T. K. Schendel, D. Sociodemographic risk factors for autism in a US metropolitan area. J Autism Dev Disord. 2007 Apr; 37 (4): 667-77.
- Croen, L. A. Najjar, D. V. Fireman, B. Grether, J. K. Maternal and paternal age and risk of autism spectrum disorders. Arch Pediatr Adolesc Med. 2007 Apr; 161 (4): 334-40.
- McGrath, J. Hypothesis: is low prenatal vitamin D a risk-modifying factor for schizophrenia?. Schizophr Res. 1999 Dec 21; 40 (3): 173-7.
- McGrath, J. J. Burne, T. H. Feron, F. Mackay-Sim, A. Eyles, D. W. Developmental vitamin D deficiency and risk of schizophrenia: a 10-year update. Schizophr Bull. 2010 Nov; 36 (6): 1073-8.
- Hediger, M. L. England, L. J. Molloy, C. A. Yu, K. F. Manning-Courtney, P. Mills, J. L. Reduced bone cortical thickness in boys with autism or autism spectrum disorder. J Autism Dev Disord. 2008 May; 38 (5): 848-56.
- Noipayak, P. The ratio of 2nd and 4th digit length in autistic children. J Med Assoc Thai. 2009 Aug; 92 (8): 1040-5.
- Buchmayer, S. Johansson, S. Johansson, A. Hultman, C. M. Sparen, P. Cnattingius, S. Can association between preterm birth and autism be explained by maternal or neonatal morbidity?. Pediatrics. 2009 Nov; 124 (5): e817-25.
- Fuller, K. E. Low birth-weight infants: the continuing ethnic disparity and the interaction of biology and environment. Ethn Dis. 2000 Autumn; 10 (3): 432-45.
- Mann, J. R. McDermott, S. Bao, H. Hardin, J. Gregg, A. Pre-eclampsia, birth weight, and autism spectrum disorders. J Autism Dev Disord. 2010 May; 40 (5): 548-54.
- Bodnar, L. M. Catov, J. M. Simhan, H. N. Holick, M. F. Powers, R. W. Roberts, J. M. Maternal vitamin D deficiency increases the risk of preeclampsia. J Clin Endocrinol Metab. 2007 Sep; 92 (9): 3517-22.
- Hibbeln, J. R. Davis, J. M. Steer, C. Emmett, P. Rogers, I. Williams, C. Golding, J. Maternal seafood consumption in pregnancy and neurodevelopmental outcomes in childhood (ALSPAC study): an observational cohort study. Lancet. 2007 Feb 17; 369 (9561): 578-85.
- Lu, Z. Chen, T. C. Zhang, A. Persons, K. S. Kohn, N. Berkowitz, R. Martinello, S. Holick, M. F. An evaluation of the vitamin D3 content in fish: Is the vitamin D content adequate to satisfy the dietary requirement for vitamin D?. J Steroid Biochem Mol Biol. 2007 Mar; 103 (3-5): 642-4.
- Cannell, J. J. On the aetiology of autism. Acta Paediatr. 2010 Aug; 99 (8): 1128-30.