RT Journal Article SR Electronic T1 Vitamin B12 and homocysteine JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1360 OP 1360 DO 10.1503/cmaj.1050170 VO 173 IS 11 A1 Brian M. Gilfix YR 2005 UL http://www.cmaj.ca/content/173/11/1360.1.abstract