Lower vitamin B12 levels could impact brain function in older adults

Meeting the minimum requirement for vitamin B12, which is needed to make DNA, red blood cells and nerve tissue, may not really be enough – especially if you are older. It can even run the risk of cognitive impairment.

A new study, led by UC San Francisco researchers, showed that older, healthy volunteers, with lower concentrations B12, but still in the normal reach, signs showed neurological and cognitive shortage. These levels were associated with more damage to the white matter of the brain – the nerve fibers that make communication between the brain brain possible – and test scores associated with slower cognitive and visual processing speeds compared to those with higher B12.

The study published in Annals of Neurology on February 10.

The researchers led by senior author Ari J. Green, MD, from the UCSF departments of neurology and ophthalmology and the Weill Institute for Neurosciences, said the results raise questions about the current B12 requirements and suggest that the recommendations must be updated .

“Earlier studies that have defined healthy amounts of B12 may have missed subtle functional manifestations of high or low levels that can influence people without causing open symptoms,” said Green, and noted that clear shortcomings of the vitamin are often associated with a type anemia. “The revision of the definition of B12 deficiency to include functional biomarkers can lead to earlier intervention and prevention of cognitive decline.”

Lower B12 correlates with slower processing speeds, brain injuries

In the study, researchers were registered 231 healthy participants without dementia or mild cognitive impairment, the average age of which was 71. They were recruited through the Brain Aging Network for Cognitive Health (Branch) study at UCSF.

Their blood B12 amounts to an average of 414.8 pmol/l, well above the American minimum of 148 pmol/l. Adapted for factors such as age, gender, education and cardiovascular risks, researchers looked at the biologically active component of B12, which offers a more accurate measure of the amount of vitamin that the body can use. In cognitive tests, participants with a lower active B12 appeared to have a lower processing speed with regard to subtle cognitive decline. Its impact was reinforced in old age. They also showed significant delays that responded to visual stimuli, indicating slower visual processing speeds and general slower brain conductivity.

MRIS unveiled a higher volume of lesions in the white matter of the participants, which can be associated with cognitive decline, dementia or stroke.

While the study volunteers were older adults, who may have a specific vulnerability to lower the levels of B12, Co-first author Alexandra Beaudrry-Richard, MSC, that these lower levels “can influence what we thought before And can influence a much larger part of the population than we realize. Research and medicine at the UCSF department of neurology and the Microbiology and Immunology department at the University of Ottawa.

In addition to redefining B12 deficiency, clinicians must supplement in older patients with neurological symptoms, even if their levels are within the normal limits. Ultimately, we have to invest in more research on the underlying biology of B12 insufficiency, because it can be a cause of cognitive decline. “

Alexandra Beaudrry-Richard, MSc, co-first author