B12 & Cognition (2011)
This study investigated B12 & cognition. This study compared markers of vitamin B12 deficiency with various measures of brain shrinkage (MRI scans) and function (neuropsychological test results) over a 5 year period. Results indicated that Methylmalonate, a specific marker of B12 deficiency, may affect cognition by reducing total brain volume. However, the effect of homocysteine (nonspecific to vitamin B12 deficiency) on cognitive performance may be mediated through increased white matter hyperintensity and cerebral infarcts.
Tangney CC, Aggarwal NT, Li H, Wilson RS, DeCarli C, Evans DA, Morris MC (2011) Vitamin B12, cognition, and brain MRI measures – A cross-sectional examination. Neurology 77:1276-1282