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The AutismLand That Neurodiversity Forgot

Decreased Brain Levels of Vitamin B12 in Aging, Autism and Schizophrenia

Science post imageDecreased 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,
Richard C. Deth


Published: January 22, 2016
DOI: 10.1371/journal.pone.0146797

Many studies indicate a crucial role for the vitamin B12 and folate-dependent enzyme methionine synthase (MS) in brain development and function, but vitamin B12 status in the brain across the lifespan has not been previously investigated. Vitamin B12 (cobalamin, Cbl) exists in multiple forms, including methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl), serving as cofactors for MS and methylmalonylCoA mutase, respectively. We measured levels of five Cbl species in postmortem human frontal cortex of 43 control subjects, from 19 weeks of fetal development through 80 years of age, and 12 autistic and 9 schizophrenic subjects. Total Cbl was significantly lower in older control subjects (> 60 yrs of age), primarily reflecting a >10-fold age-dependent decline in the level of MeCbl. Levels of inactive cyanocobalamin (CNCbl) were remarkably higher in fetal brain samples. In both autistic and schizophrenic subjects MeCbl and AdoCbl levels were more than 3-fold lower than age-matched controls. In autistic subjects lower MeCbl was associated with decreased MS activity and elevated levels of its substrate homocysteine (HCY). Low levels of the antioxidant glutathione (GSH) have been linked to both autism and schizophrenia, and both total Cbl and MeCbl levels were decreased in glutamate-cysteine ligase modulatory subunit knockout (GCLM-KO) mice, which exhibit low GSH levels. Thus our findings reveal a previously unrecognized decrease in brain vitamin B12 status across the lifespan that may reflect an adaptation to increasing antioxidant demand, while accelerated deficits due to GSH deficiency may contribute to neurodevelopmental and neuropsychiatric disorders.

Read more Decreased Brain Levels of Vitamin B12 in Aging, Autism and Schizophrenia.


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I just started my mildly-autistic son on Behavior Balance (it has B6, B9, B12, and DMG). After a week, I think I'm starting to see some good results. He doesn't seem to be as touchy, and I'm not sure, but I think his expressive language is starting to improve. Today he asked me, "Will you get my glasses while I tie my shoes?" Usually he tends to talk more or less like a toddler and refer to himself in the third person (he's 14). My jaw dropped a little!

So the B12 may be helping here...? I've heard good things about B6 and magnesium (he gets Epsom salt--magnesium sulfate--baths and he says it calms him).

Denise Anderstrom Douglass

I am low level on scientific credentials, but this study was fascinating. Low B-12 in the brain; very interesting.

Angus Files

Interesting article a good You Tube video on B12



So the pathways that put the extra carbon and three hydrogens on to vitamin B 12 -- and other vitamins so the body pathways can grab hold of them and use them is the problem?

And are they thinking that the gut microbes are missing that does that? Or does the human body actually do this themselves.

Tim Lundeen

Fascinating paper, thanks for the article.


B12 pathways was looked at in autistic children at the Chelsea and Westminster Hospital in London in the mid- nineties before the work at the Royal Free I believe at the instigation of parents. Seems to take a while for the scientists to catch up

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