Whole body monitoring and other studies of zinc-65 metabolism in patients with dermatological diseases

The retention of an oral dose of 65Zn was measured in patients with skin disease over a period of 231 days using a whole body monitor. The retention was compared with available data on healthy subjects. No significant differences were observed for the group as a whole. In a small clinical subgroup with venous leg ulcers, a lower retention and a shorter biological half life of 65Zn were found. Faecal and urinary loss of 65Zn were measured over the first 7 days, and indirectly confirmed the retention values obtained by whole body counting. Whole blood and plasma 65Zn concentrations were studied up to 192 days. No significant differences were observed when compared with other disease groups. The activity profiles of some patients appeared to confirm the liver as the organ of early preferential uptake. A close similarity of the metabolic behaviour of zinc and iron was observed. The minimum daily requirements of zinc to maintain body stores is assessed as 2.4–4.2 mg.