To the Editor.
—During the past year, ophthalmologists have been subjected to an extensive publicity campaign regarding the role of micronutrients, especially zinc supplementation in the treatment of macular degeneration. The article by Newsome et al1 in the February 1988 issue of the Archives is often quoted to substantiate this advertising. In the study done by the authors, 200 mg of zinc was given daily to patients with macular degeneration. This is a toxic amount of zinc that can produce serious complications. The recommended daily allowance is 15 mg. When more than 150 mg of zinc is taken, it can produce serious copper deficiency, sideroblastic anemia, and bone marrow depression.2 Such patients must often undergo costly and unpleasant tests, such as bone marrow biopsy, to determine the cause of the anemia. It is important for clinicians to be aware of this possible complication when prescribing large amounts of
Trempe CL. Zinc and Macular Degeneration. Arch Ophthalmol. 1992;110(11):1517. doi:10.1001/archopht.1992.01080230015002