A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Winter, 2016 | Number 1, Volume 30

Brain levels of vitamin B12 low in autism, schizophrenia

Individuals with autism or schizophrenia have unusually low brain levels of vitamin B12, according to a new study partially funded by the Autism Research Institute. 

Yiting Zhang and colleagues measured levels of different forms of cobalamin (vitamin B12) in postmortem brain samples from 12 people with autism, 9 people with schizophrenia, and 43 neurotypical controls. The neurotypical controls ranged in age from 19 weeks of fetal development through 80 years of age. 

The researchers found that in neurotypical controls, levels of total cobalamin dropped dramatically with age. There was a greater than 12-fold decrease in methylcobalamin (an active form of B12) in samples from people between 61 and 80 years of age in comparison to samples from young people. 

Individuals with autism had levels of methylcobalamin and adenosylcobalamin (another active form of B12) more than three times lower than those of age-matched neurotypical controls. The average brain level of B12 in children with autism was close to levels in brain tissue from neurotypical adults in their 50s. Lower-than-average levels of B12 persisted across the lifespan in individuals with autism or schizophrenia. 

Study coauthor Richard Deth says, “The large deficits of brain B12 from individuals with autism and schizophrenia could help explain why patients suffering from these disorders experience neurological and neuropsychiatric symptoms. These are particularly significant findings because the differences we found in brain B12 with aging, autism and schizophrenia are not seen in the blood, which is where B12 levels are usually measured.” 

The researchers say that low levels of B12 in autism and schizophrenia may stem from oxidative stress. They recommend research to determine if individuals with autism or schizophrenia could benefit from supplemental vitamin B12 and antioxidants.

Individuals with autism or schizophrenia had levels of methylcobalamin and adenosylcobalamin (two active forms of B12) more than three times lower than those of age-matched neurotypical controls.


Citations

“Decreased brain levels of vitamin B12 in aging, autism, and schizophrenia,” Yiting Zhang, Nathaniel W. Hodgson, Malav S. Trivedi, Hamid M. Abdolmaleky, Margot Fournier, Michel Cuenod, Kim Quang Do, and Richard C. Deth, PLOS ONE, January 22, 2016 (online). Address: Richard Deth, [email protected]

—and— 

“Study: Vitamin B12 levels low in brains affected by autism or schizophrenia,” Autism Speaks, January 25, 2016.