Final answer:
An adult's urine production in a 24-hour period generally does not exceed 2 liters (2000 mL). A minimum of 500 mL/day is necessary for waste removal, and amounts less than this could signal health issues such as dehydration or renal disease.
Step-by-step explanation:
The normal volume of urine produced by an adult in a 24-hour period can vary considerably but generally does not exceed 2 litres per day, which is 2000 milliliters (mL). The kidneys play a critical role in regulating water output and must produce a minimum urine volume of about 500 mL/day to excrete metabolic wastes properly. If an adult produces less than this minimum volume, it may indicate severe dehydration or renal disease, a condition known as oliguria. Conversely, excessive urine production, known as polyuria, might indicate conditions such as diabetes mellitus or diabetes insipidus.