RELATIONS OF VITAMIN-B-12, VITAMIN-B-6, FOLATE, AND HOMOCYSTEINE TO COGNITIVE PERFORMANCE IN THE NORMATIVE AGING STUDY

We investigated the relations between plasma concentrations of homocys teine and vitamins B-12 and B-6 and folate, and scores from a battery of cognitive tests for 70 male subjects, aged 54-81 y, in the Normativ e Aging Study. Lower concentrations of vitamin B-12 (P = 0.04) and fol ate (P = 0.003) and higher concentrations of homocysteine (P = 0.0009) were associated with poorer spatial copying skills. Plasma homocystei ne was a stronger predictor of spatial copying performance than either vitamin B-12 or folate. The association of homocysteine with spatial copying performance was not explained by clinical diagnoses of vascula r disease. Higher concentrations of vitamin B-6 were related to better performance on two measures of memory (P = 0.03 and P = 0.05). The re sults suggest that vitamins (and homocysteine) may have differential e ffects on cognitive abilities. Individual vitamins and homocysteine sh ould be explored further as determinants of patterns of cognitive impa irment.