RT Journal Article SR Electronic T1 Cobalamin deficiency in elderly patients JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 448 OP 450 DO 10.1503/cmaj.1041365 VO 172 IS 4 A1 Joel G. Ray A1 David E.C. Cole YR 2005 UL http://www.cmaj.ca/content/172/4/448.3.abstract