People who take certain medications may also be at risk of vitamin B12 deficiency, including, but not limited to, estrogen, H2 receptor antagonists, PPIs (Proton Pump Inhibitors), Chloramphenicol, and Metformin
However, its common for blood tests to reveal inaccurate information regarding B12 levels since a high percentage is stored in the liver and not always revealed through testing (for example, taking large amounts of folic acid has been found to mask vitamin B12 deficiency in some patients)
Nevertheless, use of metformin may decrease vitamin B 12 status: a meta-analysis of four short-term intervention trials (up to 4 months duration) in patients with type 2 diabetes found that metformin use decreased serum cobalamin concentrations by 57 pmol/L, which could have clinical implications if such patients have suboptimal vitamin B 12 status (146)
Notably, it can lead to a false-positive pregnancy test due to its molecular similarity to endogenous pregnancy HCG, which is the target of standard hCG immunoassays
Patients can discuss their symptoms, wellness goals, and treatment progress to determine the most suitable B12 injection plan
