Correspondence Zinc Supplementation in Elderly Nursing Home Residents

To the Editor—We greatly appreciated the detailed review of immune senescence and immunizations in nursing home res-idents by Fulop et al [1]. Protein-energy malnutrition and micronutrient deficien-cies, which are commonly encountered in this population [2], place these individuals at increased risk for impaired immune function and infection. We were dismayed, however, to read the incorrect interpre-tation of the results of a study that we performed that evaluated the association between serum zinc concentrations and risk of pneumonia in elderly nursing home residents [3]. In contrast to the er-roneous description of the results pro-vided by Fulop et al [1], we found that normal serum zinc concentrations in el-derly nursing home residents were asso-ciated with significantly lower incidence and shorter duration of pneumonia, re-duced number of new antibiotic prescrip-tions, and decrease in the duration of an-tibiotic use, when compared with low final zinc concentrations in those individuals [3]. The results of our study suggest that maintaining normal serum zinc concen-trations in elderly individuals might serve to reduce the incidence of pneumonia and associated morbidity. These findings are consistent with the well-documented im-portance of zinc for normal immune func-tion [4]. In addition to several studies that have documented improvements in im-mune function in elderly individuals who receive zinc supplements [5–7], there is evidence from at least one small clinical trial that suggests that zinc supplementa-tion can reduce the incidence of all infec-tions, including respiratory tract infections in the elderly population [8]. Although these preliminary findings are provocative, adequately powered, well designed, and randomized, controlled trials are needed to provide further evidence of the role of zinc supplementation in elderly nurs-ing home residents for the prevention of infection and amelioration of immune response