Possible Interactions with
Vitamin B12 (Cobalamin)
Overview
The absorption of vitamin B12 is decreased when taking medications such as
omeprazole, lansoprazole, ranitidine, cimetidine, or antacids that are often
used to treat ulcers. This interference with vitamin B12 is most likely to
result from prolonged use of more than a year.
Blood levels of vtamin B12 may also be reduced when taking metformin for
diabetes or chemotherapeutic medications for cancer, particularly
methotrexate.
