Nutraceutical: Vitamin B12

Indication: Cognitive function

Source: Neurology, September 27, 2011; 77(13):1276-82.

Research: In this study, the goal was to investigate the interrelations of serum vitamin B12 markers with brain volumes, cerebral infarcts and performance on different cognitive tests. As part of the Chicago Health and Aging Project, researchers measured homocysteine (and other markers of B12 deficiency), as well as vitamin B12 status in 121 community-dwelling participants. Approximately 4.6 years later, subjects had an MRI to measure brain volume.

Results: Concentrations of all vitamin B12-related markers, but not serum vitamin B12 itself, were associated with global cognitive function and with total brain volume. Methylmalonate levels were associated with poorer episodic memory and perceptual speed, and cystathionine and 2-methylcitrate with poorer episodic and semantic memory. Homocysteine concentrations were associated with decreased total brain volume. The homocysteine-global cognition effect was modified and no longer statistically significant with adjustment for white matter volume or cerebral infarcts. The methylmalonate-global cognition effect was modified and no longer significant with adjustment for total brain volume. Methylmalonate, a specific marker of B12 deficiency, may affect cognition by reducing total brain volume whereas the effect of homocysteine (nonspecific to vitamin B12 deficiency) on cognitive performance may be mediated through increased white matter hyperintensity and cerebral infarcts. Researchers believe vitamin B12 status may affect the brain through multiple mechanisms.