Dementia Risk Could Increase with Low Levels of Essential Vitamin

"Normal" levels of vitamin B12 might not be enough to **protect against dementia**, according to new research from the University of California, San Francisco (UCSF). The study suggests that the current standards for B12 levels could be selling us short when it comes to brain health.

The research team examined 231 healthy older adults, with an average age of 71, who showed no signs of dementia or mild cognitive impairment. Blood tests revealed an average B12 level of 414.8 pmol/L, far above the U.S. recommended minimum of 148 pmol/L. Yet even within this "normal" range, lower B12 levels were linked to slower cognitive and visual processing speeds—a subtle sign of cognitive decline.

What’s more, participants with lower levels of B12 had more lesions in the white matter of their brains, a potential warning for cognitive decline, dementia, or even stroke. The study, published in the **Annals of Neurology** on February 10, suggests that aging may amplify these effects, making the need for accurate B12 assessment even more crucial.

Senior author Dr. Ari J. Green emphasized the importance of revisiting B12 deficiency definitions. "Healthy amounts of B12 might still miss subtle issues that can affect people without obvious symptoms," he explained. Updating the criteria to include functional biomarkers could lead to earlier interventions and perhaps even prevent cognitive decline.

One of the study's co-authors, Alexandra Beaudry-Richard, pointed out that older adults might be particularly vulnerable to lower B12 levels. She cautioned that this deficiency might impact a larger portion of the population than previously recognized. Beaudry-Richard also suggested that clinicians consider B12 supplementation for older patients showing neurological symptoms—even if their B12 levels are within the established "normal" range.

Dr. Brett Osborn, a neurosurgeon and longevity expert, agreed with the findings, calling current "normal" B12 levels "grossly inadequate" for protecting the brain from age-related decline. Osborn highlighted alarming trends in the data, such as "slower processing speeds, increased white matter hyperintensities, and elevated tau protein levels—all signs of neurodegeneration." He argued that today's standards were built on outdated population averages, which poorly reflect optimal health.

Osborn recommends B-complex vitamin supplements, including B12, to maintain healthy levels of homocysteine, an amino acid linked to brain function. "Do we really need a randomized controlled trial to confirm that optimizing B12 intake benefits brain health? That’s like waiting for proof that vegetables are good for you," he quipped.

However, not everyone is ready to prescribe supplements across the board. Dr. Earnest Lee Murray, a neurologist in Tennessee, warned against "mega-doses" of vitamins, noting that excessive intake could still pose risks. He advised older adults or those at risk of cognitive decline to discuss B12 testing with their physician, including markers that assess B12 absorption, not just levels in the blood.

The takeaway? It might be time to rethink what "normal" means in health. After all, as Osborn aptly put it, "Who wants to be normal when you can be optimal?"