Many clinicians request the analysis of essential elements in urine specimens to evaluate nutritional status and the efficacy of mineral supplementation during metal detoxification therapy. Metal detoxification agents can significantly increase the excretion of specific nutrient elements such as zinc, copper, manganese and molybdenum. Chromium metabolism authorities suggest that 24-hour chromium excretion likely provides the best assessment of chromium status. Early indication of renal dysfunction can be gleaned from urinary wasting of essential elements such as magnesium, calcium, potassium and sodium in an unprovoked specimen. Variability in urine volume can drastically affect the concentration of elements. To compensate for urine dilution variation, elements are expressed per unit creatinine for timed collections. For 24-hour collections, elements are reported as both units per 24 hours and units per creatinine.