Copper status and urinary and salivary copper in young men at three levels of dietary copper

Eleven young men were confined to a metabolic research unit for 90 d to determine the effect of the amount of dietary copper on copper nutriture. The study was divided into three metabolic periods (MP): 1) with an adequate-copper diet (1.68 mg/d) for 24 d, 2) with a low-copper diet (0.79 mg/d) for 42 d, and 3) with a high-copper diet (7.53 mg/d) for 24 d. Three indices of copper status, urinary copper, and salivary copper were determined at intervals throughout the study. Neither copper status, urinary copper, nor salivary copper differed among MPs. Sweat collections from three subjects suggested that losses of copper through sweat were very low and would not contribute significantly to copper balance. These results suggest that an amount of dietary copper slightly less than 0.8 mg/d is adequate to maintain copper status for greater than or equal to 42 d in normal, healthy men and that neither urinary nor salivary copper is affected by the amount of Cu in the diet.