A new study from the University of California San Francisco has shed light on the relationship between decreased vitamin B12 levels and an increased risk of dementia in older adults. The research, published in the Annals of Neurology on Feb. 10, reveals that what is considered “normal” levels of vitamin B12 may not be sufficient to protect against cognitive decline.
The study focused on 231 healthy older adults, with an average age of 71, who did not have dementia or mild cognitive impairment. Blood tests showed that their B12 levels averaged 414.8 pmol/L, well above the recommended minimum level in the U.S. of 148 pmol/L. Participants with lower B12 levels exhibited slower cognitive and visual processing speeds, indicating subtle cognitive decline, particularly as they aged.
Implications of Lower B12 Levels on Brain Health
According to the researchers, individuals with lower B12 levels also displayed more lesions in the white matter of their brains, which can serve as a warning sign of cognitive decline, dementia, or stroke. The findings underscore the importance of reevaluating current B12 requirements, as the study suggests that existing benchmarks may not adequately address the functional manifestations of high or low B12 levels that impact cognitive health.
“While participants with B12 levels within the normal range may not exhibit overt symptoms, our study indicates clear signs of neurological impairment,” explained senior author Dr. Ari J. Green from the UCSF Departments of Neurology and Ophthalmology. This insight suggests that the definition of B12 deficiency may need to be revised to incorporate functional biomarkers for earlier intervention and prevention of cognitive decline.
Expert Insights on Vitamin B12 Supplementation
Commenting on the study, Dr. Brett Osborn, a Florida neurosurgeon and longevity expert, emphasized that even individuals with B12 levels considered “normal” by current medical standards demonstrated neurological impairments. He recommended supplements of B-complex vitamins, including B12, to maintain healthy levels of homocysteine, an amino acid associated with brain function.
Osborn’s perspective aligns with the call for updating what constitutes “normal” B12 levels, as the study suggests that relying on population averages may not be sufficient to protect against age-related cognitive decline. He stressed the importance of defining health by optimal levels rather than average values within an increasingly unhealthy population.
Dr. Earnest Lee Murray, a board-certified neurologist, echoed the need for redefining B12 deficiency criteria based on the findings of the study. While he cautioned against excessive vitamin supplementation, he recommended that older adults or individuals at risk of cognitive decline undergo testing not only for B12 levels but also for other markers indicating potential absorption issues.
This study underscores the importance of monitoring vitamin B12 levels and considering supplementation in older adults to safeguard cognitive health. By reevaluating conventional benchmarks and focusing on optimal rather than average values, individuals can take proactive steps to protect their brain function and overall well-being. Stay tuned for further updates on this evolving research area.