You are what you eat: ophthalmological manifestations of severe B12 deficiency.

Severe B12 vitamin deficiency due to diminished dietary intake is a known cause of severe pancytopenia with bleeding diathesis. The authors report a case with sudden-onset bilateral vision loss, severe pancytopenia and multiple organ failure secondary to B12 vitamin deficiency in a patient with a strict vegetarian diet. On funduscopic examination the patient had multiple bilateral exuberant haemorrhages in all retinal layers. Five months after presentation, he had a complete visual recovery without ophthalmological intervention.