RT Journal Article SR Electronic T1 Daily folic acid supplementation for 3 years improved cognitive function in older persons JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 83 OP 83 DO 10.1136/ebm.12.3.83 VO 12 IS 3 YR 2007 UL http://ebm.bmj.com/content/12/3/83.abstract AB