31st July 2023

A 59-year-old female is found to have a low vitamin B12 level on routine bloods

A 59-year-old female is found to have a low vitamin B12 level on routine bloods. She denies a change in bowel habit. She has a history of type 2 diabetes mellitus and chronic obstructive pulmonary disease. She is vegetarian but not vegan. Her haemoglobin and MCV are normal. Intrinsic factor and parietal antibodies are negative.

What is the most likely cause of her low B12 levels?

Select the SINGLE most appropriate option from the list below. Select ONE option only.