Correspondence

Blindness in a Vegan

N Engl J Med 2000; 343:585-586August 24, 2000

Article

To the Editor:

Enthusiasm is laudable, but simplicity is even better.

The reports by Li and McKay and by Milea et al. (March 23 issue)1,2 surprised me because of the excessive diagnostic testing used in patients who were anemic and nutritionally deficient as a result of strict, unsupplemented vegan diets. The dietary histories of the two patients should have been sufficient for understanding the etiology and pathogenesis of their conditions and for determining their treatment. I am puzzled by the need for small-bowel x-ray studies, endoscopy and multiple gastric biopsies, and mitochondrial-DNA analysis at the start.

Harvey E. Finkel, M.D.
92 Dean Rd., Brookline, MA 02445-4244

2 References

1. 1

   Li K, McKay G. Ischemic retinopathy caused by severe megaloblastic anemia. N Engl J Med 2000;342:860-860
   Full Text | Web of Science | Medline

2. 2

   Milea D, Cassoux N, LeHoang P. Blindness in a strict vegan. N Engl J Med 2000;342:897-898
   Full Text | Web of Science | Medline

To the Editor:

The two reports of nutritional deficiency in vegans include a case of anemia-associated retinopathy, in which the fundus photographs were rotated 90 degrees from their proper orientation, and a case of optic neuropathy and peripheral neuropathy. The authors of the latter report make the undocumented assertion that vegetarians are at risk for nutritional deficiency if they do not receive vitamin supplementation. Although I agree that vegans should include a source of vitamin B₁₂ in their diet, there is no evidence that supplementation of other nutrients is necessary or even desirable in those following a balanced diet.

Remarkably, both of the patients described in these reports were deficient in folate, despite the fact that numerous studies have found that both vegan and nonvegan vegetarians tend to have higher intakes of folate and higher plasma levels of folate than do omnivores.1-3 These findings are not surprising, considering that leafy green vegetables, legumes, and several fruits are among the richest sources of folate. The patient described by Milea et al. was also said to be deficient in vitamins C and E, both of which are derived primarily from plant sources.

Clearly, then, these patients were not usual vegans but rather persons who were following anomalous vegan practices. To impute the tendency toward nutritional deficiency in such persons to the majority of vegans, who follow normative dietary practices, is inappropriate and, unfortunately, all too common in the medical literature. Vegetarian diets rich in a variety of fruits and vegetables represent the ideal from a disease-prevention standpoint, undoubtedly because they provide the phytochemicals that are so lacking in the average Western diet.

Jay B. Lavine, M.D.
P.O. Box 43126, Tucson, AZ 85733-3126

3 References

1. 1

   Haddah EH, Berk LS, Kettering JD, Hubbard RW, Peters WR. Dietary intake and biochemical, hematologic, and immune status of vegans compared with nonvegetarians. Am J Clin Nutr 1999;70:Suppl:586S-593S
   Web of Science | Medline

2. 2

   Harman SK, Parnell WR. The nutritional health of New Zealand vegetarian and non-vegetarian Seventh-day Adventists: selected vitamin, mineral and lipid levels. N Z Med J 1998;111:91-94
   Medline

3. 3

   Fenech M, Rinaldi J. A comparison of lymphocyte micronuclei and plasma micronutrients in vegetarians and non-vegetarians. Carcinogenesis 1995;16:223-230
   CrossRef | Web of Science | Medline

Author/Editor Response

The authors reply:

To the Editor: We agree with Finkel that the dietary history helped us to determine the right diagnosis in our patient, but diagnostic testing was necessary to rule out other possible causes of his condition, such as compression or mitochondrial disease. It is important to exclude other causes of optic neuropathy before accepting a nutritional origin.1

Our patient, being an “unusual” vegan, as Lavine suggests, had not only an unsupplemented but also an inappropriately strict vegan diet. He had no nutritional counseling and retrospectively admitted excessive restriction of his diet, although he did not seem to be anorexic or mentally ill. Several nutritional deficiencies have been reported in vegans,2,3 but the unexpected low levels of folate and vitamins C and E in our patient may have been caused by inadequate nutrition, probably due to a diet that was not in accordance with recommended vegan practices. Therefore, appropriate guidance and nutritional supplementation could have been useful in this particular case.

Dan Milea, M.D.
Nathalie Cassoux, M.D.
Phuc LeHoang, M.D., Ph.D.
Groupe Hospitalier Pitié–Salpêtrière, 75651 Paris CEDEX 13, France

3 References

1. 1

   Miller NR, Newman NJ. The essentials: Walsh & Hoyt's clinical neuro-ophthalmology. 5th ed. Baltimore: Williams & Wilkins, 1999:664.
   

2. 2

   Zmora E, Gorodischer R, Bar-Ziv J. Multiple nutritional deficiencies in infants from a strict vegetarian community. Am J Dis Child 1979;133:141-144
   Web of Science | Medline

3. 3

   Remer T, Neubert A, Manz F. Increased risk of iodine deficiency with vegetarian nutrition. Br J Nutr 1999;81:45-49
   Web of Science | Medline