Co-first author Alexandra Beaudry-Richard emphasized that lower B12 levels could impact cognition more significantly than previously understood, potentially affecting a broader population.

A recent study published in the Annals of Neurology revealed that older individuals with vitamin B12 levels deemed healthy still showed signs of cognitive decline and brain damage.

MRI scans further indicated that participants with lower active B12 levels had a higher volume of lesions in the white matter, which may be associated with cognitive decline and conditions such as dementia or stroke.

There is a growing call for further research into the biological implications of B12 insufficiency, as it may represent a preventable factor in cognitive decline.

Vitamin B12 is crucial for DNA synthesis, red blood cell formation, and nerve health, and is mainly sourced from animal products, with alternatives available for those following vegan or vegetarian diets.

Participants in the study had an average B12 level of 414.8 pmol/L, significantly above the U.S. minimum of 148 pmol/L, yet those with lower active B12 levels demonstrated slower cognitive processing speeds.

Interestingly, the study found a connection between higher levels of inactive B12 and increased tau protein levels, which are linked to neurodegenerative diseases like Alzheimer's.

Senior author Ari J. Green, MD, pointed out that previous research may have missed subtle effects of B12 levels that contribute to cognitive issues without presenting clear symptoms.

The researchers advocate for redefining B12 deficiency to include functional biomarkers and suggest that clinicians consider supplementation for older patients exhibiting neurological symptoms, even if their B12 levels are normal.