['An intervention study was performed to determine if supplement containing folic acid, vitamin B', 'One hundred and four participants with hyperhomocysteinemia were recruited in Tianjin, China, aged 55-94 years old. Fifty-seven individuals with hyperhomocysteinemia were included in the intervention group (vitamin B group, which received 800\xa0µg/day of folate, with 10\xa0mg of vitamin B', 'The BCAT total score and four sub-tests scores (digit copy, Chinese character rotation, digital working memory, and recognition of meaningless figure) of BCAT at 14 weeks significantly increased only for the vitamin B group. Serum total homocysteine (tHcy) levels significantly decreased in the intervention group, while serum concentrations of folate, vitamin B'] Does b vitamin supplementation improve cognitive function in the middle aged and elderly with hyperhomocysteinemia?