An 11-year-old boy with a limited diet has developed severe and lasting vision loss, according to a case report published online October 2 in JAMA Pediatrics journal. The boy recovered partial sight after 6 weeks of intense vitamin A supplementation.

The report calls for greater awareness of the link between nutrient deficiency and healthy vision – not only in impoverished nations but in wealthy nations where food is abundant.

According to his parents, the boy consumed only 6 foods - potato, pork, lamb, apples, cucumber and Cheerios - to avoid dietary allergens that might trigger eczema flare-ups. His vision deteriorated over the course of 8 months, leading to light sensitivity, night blindness and vision so poor that he could only detect hand motions from 30 cm away.

Upon examination, his pupils appeared intact and reacted equally to light, but dry patches of keratin dotted his conjunctiva and further inspection revealed mild damage to his optic nerve.

Clinicians analyzed the child’s blood and found dangerously low levels of vitamin A: 14.33 mug/dl, significantly below the healthy cutoff of 20.06 mug/dl. They treated the child with two daily doses of 200,000 IU vitamin A, followed by another megadose 2 weeks later.

After 6 weeks, the child’s conjunctiva appeared healthy and his vision improved slightly to 20/800, though he remained legally blind.

Vitamin A deficiency is a leading cause of preventable childhood blindness. About one-third of the world’s children lack adequate levels of vitamin A, a nutrient found in carrots, fish, liver, butter and leafy green vegetables. Many of these children live in sub-Saharan Africa and South Asia, where nutrient-rich foods are scarce. But physicians should be aware that children in wealthy nations are susceptible, too, particularly individuals with dietary allergies, sensory sensitivities or other conditions that limit food variety.