Normal vitamin B12 levels may not be enough to protect the brain, study finds

Current recommendations for vitamin B12 levels might be too low to adequately protect the aging brain, according to new research from the University of California, San Francisco (UCSF).

The study, published in the journal Annals of Neurology, analyzed 231 healthy individuals aged 71 on average. Researchers focused on the active form of vitamin B12, which better indicates how much the body can utilize. Findings revealed that older participants with lower levels of active B12, even those considered within the "normal" range, exhibited slower cognitive task performance and reduced visual information processing speed.

Brain imaging using MRI also showed a higher number of white matter lesions in these individuals. These lesions are associated with cognitive decline, dementia, and an increased risk of stroke. Neurologist Ari D. Grin from UCSF's Weill Institute for Neurosciences suggested that existing criteria for diagnosing vitamin B12 deficiency might miss early neurological changes.

Scientists warn that older adults are particularly vulnerable to B12 deficiency due to decreased absorption with age, medication side effects, digestive issues, and diets low in animal products. Co-author Aleksandra Bodri-Rišar believes that "borderline low" vitamin B12 levels could impact cognitive functions more significantly and affect a larger population than previously thought. Redefining deficiency could lead to earlier treatment and prevention strategies for cognitive impairment.