Vitamin B12, Mayo Clinic, Vitamin B12, Fact Sheet for Consumers, National Institutes of Health, Office of Dietary Supplements, Pernicious anemia, Cleveland Clinic, Ganipisetti VM, Naha S
In contrast, the EFSA reports that a cut-off value of 750 nmol/l is used for the diagnosis of cobalamin deficiency for all ages (EFSA, 2015)
These could include: Complete blood count (CBC)
Common occurrence of atrophic gastritis in an ageing non-hospitalised population: an autopsy study
Common Side Effects When side effects occurred, they were typically mild, transient, and similar in frequency to placebo groups: Reported Adverse Effects Most Common (occurring in small percentage of participants): Mild to moderate headaches (most frequently reported, often resolving with continued use) Injection site reactions (minor redness, swelling, or irritation at injection site) Gastrointestinal effects (particularly at higher oral doses: mild nausea, diarrhea, flatulence) Fatigue (reported occasionally during initial adaptation period) Rare Events: One case of chest tightness was deemed possibly related to treatment in safety trials
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
