Project Description: Low vitamin B12 and folate status are common conditions in the elderly and have been linked to a greater risk of Alheimer's disease. Our objective was to examine the association of plasma vitamin B12 and red blood cell (RBC) folate status with cerebral volumes in a longitudinal population-based cohort of older adults. 501 dementia-free subjects at baseline (aged 60-97 years; 298 women and 203 men) from the Swedish National Study of Aging and Care in Kungsholmen (SNAC-K), with repeated structural brain magnetic resonance imaging (MRI) scans at 2-3 occasions over 6 years, were recruited. The association of baseline vitamin B12 and RBC folate with the rate of brain volume loss was examined with the use of linear mixed models. After adjusting for several potential confounders including age, sex, education, the use of vitamins supplements, RBC folate levels, chronic conditions, hemoglobin, and plasma albumin, higher baseline plasma vitamin B12 concentrations were associated with decreased rate of total brain tissue (TBT) and grey matter (GM) volume loss over 6 years. β coefficient and standard error (SE) were 0.0020 (0.001), p = 0.002 for TBT; and they were 0.0013 (<0.001), p = 0.016 for GM. These associations remained significant even after excluding 28 incident dementia cases [β (SE): 0.0019 (<0.001); p = 0.003 for TBT and 0.0014 (<0.001); p = 0.010 for GM]. RBC folate levels had no longitudinal relationship with cerebral volumes. These results indicate that higher plasma concentrations of vitamin B12 are associated with decreased rate of brain volume loss. Randomized controlled trials are needed to determine the impact of vitamin B12 supplementation on preventing cognitive decline in older adults.
© 2014 Published by Elsevier Inc.