Classically presents with megaloblastic anemia, but can also present with peripheral neuropathy and other neuropsychiatric complaints.
Older people, patients with chronic malabsorption, patients with a history of gastric resection or bypass, and those taking certain medications (metformin, proton-pump inhibitors) are at risk.
Early diagnosis is critical in preventing and halting the progression of neurologic disorders such as peripheral neuropathy and dementia.
Methylmalonic acid and homocysteine levels may help to diagnose vitamin B12 deficiency at an early, asymptomatic state.
Once vitamin B12 deficiency is confirmed, the cause should be searched for.
High-dose oral therapy may be as effective as parenteral vitamin B12 in the treatment of vitamin B12 deficiency.