Folic acid and vitamin B12 for prevention of cognitive decline in older people with depression
The relevance of B-vitamins for prevention of cognitive decline or risk of dementia is uncertain. Walker et al. reported the results of a randomized, placebo-controlled trial of 400 μg of folic acid and 100 μg of vitamin B12 for 2 years in 900 adults aged between 60 and 74 years old who had depression. Cognitive function was assessed by the Telephone Interview for Cognitive Status-Modified (TICS-M) and Brief Test of Adult Cognition by telephone and an Informant Questionnaire on Cognitive Decline. Supplementation with folic acid and vitamin B12 significantly improved total TICS-M scores, and TICS-M scores for immediate and delayed recall. However, folic acid and vitamin B12 had no significant effects on the other cognitive tests at 24 months. The findings of this trial are difficult to interpret because the overall effects are modest, the population studied only relates to 4% of the general population and because of the inclusion of essential covariates at baseline in the mixed models used for the analysis. Moreover, the results are not consistent with those of the previous trials that have addressed this question in the general population with or without prior cardiovascular disease. The findings warrant corroboration by detailed meta-analyses of all the available trials that addressed this topic. © 2012 Future Medicine Ltd.