Correspondence
Blindness in a Strict Vegan
N Engl J Med 2000; 342:897-898March 23, 2000
- Article
To the Editor:
Vegetarians are at risk for nutritional deficiency if they do not receive vitamin supplementation. We report a case of severe bilateral optic neuropathy in a patient who had been a vegan for many years and who did not take vitamin supplements. The patient, a 33-year-old man who had started a strict vegetarian diet at the age of 20 years, was referred for evaluation of progressive visual loss. “Improved health” was the reason for the diet, which contained no eggs, dairy products, fish, or other sources of animal proteins. He did not smoke or use alcohol, and his medical history was unremarkable.
Examination showed severe bilateral optic neuropathy with very poor vision (less than 20/400 in both eyes), central scotomata, dyschromatopsia, and atrophy of the optic disks. We found no evidence of a compression of the visual pathway or of a toxic, infectious, or inflammatory cause of the blindness. Mitochondrial-DNA analysis showed no mutation for Leber's hereditary optic neuropathy. On neurologic examination, there was a sensory peripheral neuropathy, confirmed by electrophysiologic studies. The cerebrospinal fluid was normal, including the opening pressure. The remainder of the general examination showed no abnormalities.
The plasma level of folate was low (5.4 nmol per liter; normal range, 7.5 to 28), as were the levels of vitamin B1 (4 nmol per liter; normal range, 6 to 40) and vitamin B12 (114 pmol per liter; normal range, 150 to 720). There were also deficiencies of vitamins A, C, D, and E and zinc and selenium, but plasma levels of iron, ferritin, vitamin B6, and nicotinamide were normal. The patient had megaloblastic anemia (hemoglobin level, 10.5 g per liter; mean corpuscular volume, 110 μm3), which was not due to pernicious anemia (there were no anti–parietal-cell or anti–intrinsic-factor antibodies, upper gastrointestinal endoscopy showed normal findings, and multiple biopsies showed no gastric atrophy) or other causes of malabsorption. After treatment with intramuscular vitamin B12 (1000 μg daily for one week) and oral multivitamin supplementation, the hemoglobin level was normal and the sensory neuropathy had disappeared, but there was no recovery of vision.
Vitamin B12 deficiency in vegetarians may cause neurologic disturbances.1,2 Moreover, deficiencies of vitamins B12 and B1 may be responsible for optic neuropathy associated with nutritional factors.3 Amblyopia and painful neuropathy have been reported in cases of dietary deprivation in prisoners during World War II, and more recently, dietary factors were noted in the Cuban epidemic of optic neuropathy.4 The optic neuropathy in our patient was apparently related to deficiencies of vitamins B12 and B1, but other associated deficiencies may have had a role. Vitamin supplementation is essential in persons who adhere to a strict vegetarian diet, especially because vitamin deficiencies may cause severe, irreversible optic neuropathy.
4 ReferencesDan Milea, M.D.
Nathalie Cassoux, M.D.
Phuc LeHoang, M.D., Ph.D.
Groupe Hospitalier Pitié–Salpêtrière, 75651 Paris CEDEX 13, France1
Ashkenazi S ,Weitz R ,Varsano I ,Mimouni M . Vitamin B12 deficiency due to a strictly vegetarian diet in adolescence. Clin Pediatr (Phila) 1987;26:662-663
CrossRef | Web of Science | Medline2
Renault F ,Verstichel P ,Ploussard JP ,Costil J . Neuropathy in two cobalamin-deficient breast-fed infants of vegetarian mothers. Muscle Nerve 1999;22:252-254
CrossRef | Web of Science | Medline3
Miller NR, Newman NJ. Walsh and Hoyt's clinical neuro-ophthalmology. 5th ed. Vol. 1. Baltimore: Williams & Wilkins, 1998:663-79.
4
The Cuba Neuropathy Field Investigation Team
Full Text | Web of Science | Medline
- Citing Articles (3)
