Oral zinc therapy in geriatric patients with selected skin manifestations and a low plasma zinc level.

A geriatric population comprising 585 inhabitants of an institution for the aged was studied. Twenty-six persons with a mean age of 82 years were selected because of skin manifestations suggestive of chronic zinc deficiency. In 10 of the patients a subnormal plasma zinc level was found. This hypozincaemic group underwent a 4 week trial with zinc sulphate tablets, 0.6 g daily. The therapy failed to alleviate the skin condition in any of the patients, thus indicating that the changes were not caused by zinc deficiency. In the hypozincaemic group, plasma albumin was subnormal in all patients and significantly lower than in the normozincaemic subjects. The correlation between plasma zinc and plasma albumin levels in all 34 patients studied was highly significant (rs = 0.69, p less than 0.001). As plasma albumin tends to fall to subnormal concentrations with age, this explains why plasma zinc may be low in the elderly without indicating a state of zinc deficiency. After 2 and 4 weeks' zinc therapy, the mean plasma zinc concentration of the hypozincaemic group rose significantly from 9.5 to 17.6 and 23.4 mumol/1. This increase is higher than the rise observed in younger patients receiving an identical zinc sulphate dosage.