An oral zinc loading test in psoriasis

Changes of zinc in body fluids were evaluated in 12 patients with extensive psoriasis and compared with those of 11 healthy volunteers, using an oral zinc loading test. Plasma zinc levels and urinary zinc excretion were measured by atomic absorption spectrophotometry. No significant difference was found between plasma zinc levels and urinary zinc excretion following an overnight fast. Both groups showed extensive increases in urinary zinc excretion following the loading test. The peak levels of plasma zinc were significantly lower in the psoriatic patients two and four hours after zinc ingestion (P less than .01 and P less than .02, respectively).