Vitamin B12 in low normal range linked to poor brain health

Posted on Wed, 30 Mar 16

You don’t need to be deficient in vitamin B12 to experience adverse effects on memory and brain structure, levels in a “low normal” range are enough to be linked to problems suggests a new study.  

Vitamin B12 deficiency (<150 pmol/L) has been linked to serious mental health issues including structural brain changes, cognitive decline and dementia but the effects of low-normal levels (150–300 pmol/L) are less appreciated. But while not considered a deficiency low-normal vitamin B12 may still be linked to poor brain health, according to a new study.  

In the study a group of women (aged 50—80 years) with mild cognitive impairment (MCI) had their blood vitamin B12 levels checked and compared to memory function test results and the volume and microstructure of the hippocampus, as measured with magnetic resonance imaging (MRI).

The results revealed that those with with low-normal vitamin B12 levels had significantly poorer memory performance than did those with high-normal vitamin B12. Also, the microstructure integrity of the hippocampus was lower and partially explained the effect of low vitamin B12 on memory performance. 

Commenting on their discovery the study investigators noted that “the current results suggest that higher cutoffs for serum vitamin B12 deficiency (e.g., 300 pmol/L) and earlier supplementation in older adults, particularly those with incipient dementia, might be advisable, which is an assumption to be addressed in future randomized controlled intervention trials.”

Reference: 

Köbe T, Witte AV, Schnelle A, et al. Vitamin B-12 concentration, memory performance, and hippocampal structure in patients with mild cognitive impairment. Am J Clin Nutr. 2016 Feb 24. pii: ajcn116970. [Epub ahead of print]