Low Brain Levels of Vitamin B12 in Schizophrenia, Autism Patients

 Vitamin B-12, or Cobalamin, is the largest and most complex vitamin currently known to man. A slight deficiency of vitamin B-12 can lead to anaemia, fatigue, mania, and depression, while a long term deficiency can cause permanent damage to the brain and central nervous system. Vitamin B12 can only be manufactured by bacteria and can only be found naturally in animal products, however, synthetic forms are widely available and added to many foods like cereals. Some of the food sources of vitamin B12 include shellfish, liver, fish, crustaceans (crab), fortified soy products, fortified cereals-all bran, red meat, low fat dairy and eggs.

While brain levels of Vitamin B12 decrease naturally with age, individuals with schizophrenia and autism tend to experience a premature decrease, showing far lower brain levels of B12 than healthy people of similar age, according to a new study.

For example, compared to non-autistic children under age 10, kids with autism were found to have three times lower brain levels of Vitamin B12; a level more comparable to healthy adults in their 50s.

“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,” said lead researcher Richard Deth, Ph.D., professor of pharmacology at Nova South Eastern University’s (NSU) College of Pharmacy.

“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.”

For the study, an international research team analyzed and compared brain tissue from otherwise healthy deceased donors and donors with autism or schizophrenia. They found that healthy elderly people in the age range of 61-80 have about three times lower levels of total brain B12 than younger age groups, which is a result of normal aging. This decrease may help adjust brain metabolism to sustain its function across the lifespan.

An active form of B12 called methylcobalamin, or methyl B12, supports normal brain development by managing a process known as epigenetic regulation of gene expression.

Significantly, the brain level of methyl B12 was found to be more than 10 times lower in healthy elderly people than in healthy younger people. A lower than normal level of methyl B12 in the brain could negatively alter neurodevelopment in younger years,  could disrupt learning and memory later in life.

Both autism and schizophrenia are linked to oxidative stress, also found to be a significant contributor in the aging process. The researchers believe that oxidative stress may underlie the lowered brain B12 levels observed in this study. The findings suggest the need for further research to determine if the use of supplemental methyl B12 and antioxidants like glutathione could help prevent oxidative stress and potentially be used as a treatment for these conditions.

The research is published in the online journal Public Library of Science One (PLOS One).