RT Journal Article SR Electronic T1 Update on the evidence for oral B12 supplements to treat deficiency JF Drug and Therapeutics Bulletin JO Drug Ther Bull FD BMJ Publishing Group Ltd SP 9 OP 9 DO 10.1136/dtb.2018.000057 VO 57 IS 1 YR 2019 UL http://dtb.bmj.com/content/57/1/9.abstract AB