Low Vitamin B12 Status Linked to Decreased Brain Volume in Elderly.

A recent study at the University of Oxford found low vitamin B12 status is linked to a decrease in brain volume (Neurology. 2008; 71:826-32). This prospective study was conducted over a five-year period with subjects being evaluated annually using clinical examination, MRI scans, and cognitive testing. Subjects were 107 community-dwelling volunteers aged 61 to 87 years who did not have cognitive impairment at enrollment. Researchers found that the decrease in brain volume was greater among those with lower vitamin B12 and holotranscobalamin levels, and higher plasma total homocysteine and MMA (methylmalonic acid) levels at baseline. This association remained significant after adjustment for age, sex, education, initial brain volume, cognitive test scores, systolic blood pressure, creatinine, Apolipoprotein E (a marker of late-onset Alzheimer’s Disease), total homocysteine, and folate. Vitamin B12 levels in the bottom one third of the population was associated with an increased rate of brain volume loss. The association was similar for low levels of holotranscobalamin. Researchers stated that low vitamin B12 status should be further investigated as a modifiable cause of brain atrophy and of likely subsequent cognitive impairment in the elderly.