Iron, copper and zinc levels in urine: relationship to various individual factors

Urinary Fe, Cu and Zn levels were determined in healthy people from S/C de Tenerife. Males showed higher (p < 0.01) urinary levels (micrograms/L and microgram per day) of Zn than females. However, females had higher daily urinary Fe and Cu excretions per kg of body weight (p < 0.05) than males. Urinary metal concentration, expressed as mg metal per g CT, better reflects daily excretion. Urinary levels of Zn and Cu were within the reference values, but the urinary levels of Fe were lower than that in most of the published data. An increase in daily Fe, Cu and Zn excretion (micrograms per day) with age up to 30 years was observed. An increase with weight and height was also observed. Concentrations and excretions of Zn were significantly (p < 0.015) lower when the urinary pH was above 7. With respect to the frequency of consumption of rich protein food, rich fiber food, coffee, tobacco, or alcohol, only significantly (p = 0.015) higher Zn concentrations and higher (p = 0.091) excretions were found in people that consume alcohol more than 3 times a week. A significant depletion of urinary Zn and Cu concentration and Fe excretion was found in the subjects who usually did physical exercise. Positive intermetallic correlations among the concentrations and excretions of the metals investigated were observed.