A mild vitamin B12 deficiency is linked to a higher risk for accelerated cognitive decline in older adults, suggests an observational study by researchers at Tufts University.
Researchers looked at data from 549 men and women enrolled in the Framingham Heart Study. The average age was 75 years old.
Based on their vitamin B12 blood levels, the subjects were divided into five groups. Researchers focused on scores from the Mini-Mental State Examination (MMSE) — a short list of questions often used to screen for dementia.
Being in the two lowest B12 groups was associated with significantly accelerated cognitive decline, based on an analysis of test scores given over a period of eight years.
“Men and women in the second lowest group did not fare any better in terms of cognitive decline than those with the worst vitamin B12 blood levels. Over time, their MMSE scores declined just as rapidly,” said Martha Savaria Morris, Ph.D., an epidemiologist at Tufts University.
“Rapid neuropsychiatric decline is a well-known consequence of severe vitamin B12 deficiency, but our findings suggest that adverse cognitive effects of low vitamin B12 status may affect a much larger proportion of seniors than previously thought.”
The participants in this study were mostly Caucasian women who were at least high school graduates. The authors said future research might include more diverse populations and explore whether vitamin B12 status affects particular cognitive skills, since the current results show only a general picture of decline.
“While we emphasize our study does not show causation, our associations raise the concern that some cognitive decline may be the result of inadequate vitamin B12 in older adults, for whom maintaining normal blood levels can be a challenge,” said Paul Jacques, D.Sc., the study’s senior author and director of the Nutrition Epidemiology Program at Tufts.
The study is published in the Journal of the American Geriatrics Society.