Final answer:
The nurse's instruction to maintain a fluid intake of at least 2500 mL per day in patients taking calcium supplements is to prevent the formation of kidney stones by ensuring that excess calcium is excreted in the urine.
Step-by-step explanation:
The nurse advises patients taking supplemental calcium to maintain a fluid intake of at least 2500 mL daily to prevent the formation of kidney stones. Increased fluid intake helps to dilute urine and increases urinary flow, significantly reducing the concentration of calcium and other minerals that can crystallize into kidney stones.
Adequate hydration is essential to ensure that any excess calcium from supplements is excreted in the urine without forming stones.
It's important to note that calcium homeostasis involves the intricate interaction of PTH, vitamin D, and calcitonin, influencing the urinary, skeletal, endocrine, and digestive systems.
The urinary excretion of calcium is vital for maintaining this balance. In adults, normally the kidneys can excrete any extra dietary calcium, but in conditions of hypercalcemia, the renal threshold for calcium can become abnormal, further emphasizing the importance of maintaining adequate fluid intake.