Low vitamin B12 intake may accelerate cognitive decline

December 12, 2012

A new US study says that older adults who are mildly vitamin B12 deficient may be at higher risk of cognitive decline.

In the observational study, the vitamin B12 blood concentrations and the cognitive performance (measured by a short list of questions and tasks commonly used to screen for dementia) were measured in 549 men and women, average age 75 years, over a period of eight years (1). The study results showed that the par-ticipants with the lowest blood vitamin B12 levels had a significantly accelerated cognitive decline compared to those with adequate levels. Even those participants with moderate insufficient levels showed a more rapidly loss of cognitive functions.

The researchers commented that while rapid neuropsychiatric decline is a well-known consequence of severe vitamin B12 deficiency, the new findings suggest that adverse cognitive effects do already happen at a mildly deficient status. Thus, the consequences of insufficient vitamin B12 intake may affect a much larger propor-tion of seniors than previously thought.

Animal proteins (e.g., lean meats, poultry and eggs) are good sources of vitamin B12. Since older adults may be less able to absorb vitamin B12 directly from food, the USDA's 2010 Dietary Guidelines for Ameri-cans recommend that people over 50 years-old incorporate B12 fortified foods or supplements into their diets.


  1. Morris M. S. et al. Vitamin B-12 and folate status in relation to decline in scores on the mini-mental state examination in the Framingham Heart Study. Journal of the American Geriatrics Society. 2012; 60(8):1457–1464.