A 60 year old man presented with numbness of both feet for 2 months, and was found to have isolated peripheral neuropathy secondary to underlying vitamin B12 deficiency.

He was diagnosed with type 2 diabetes mellitus 6 years ago, which is well controlled on Metformin alone. His medical history is otherwise normal.

He takes a mixed diet, and is on no other medications. A full blood count, blood film, iron studies, reticulocyte count and folate levels are all normal.