Background: Popular media have highlighted the risks for poor cardiovascular health, obesity, and cancer associated with junk food, but poor nutrition can also permanently damage the nervous system, particularly vision.

Objective: To alert clinicians of visio risks associated with a diet restricted to junk food.

Case Report: A 14-year-old boy presented to his family practitioner with tiredness. He was a “fussy eater” but was otherwise well and took no medications. Tests found macrocytic anemia and low vitamin B 12 level but no antibodies to intrinsic factor or tissue transglutaminase. He was treated with vitamin B 12 injections and dietary advice.

At age ...