Which of the following is a recognized cause of hypocalcemia?

Prepare for the Adult-Gerontology Acute Care Nurse Practitioner Test. Study with interactive quizzes and detailed explanations. Boost your exam readiness with our diverse question formats and in-depth content coverage.

Multiple Choice

Which of the following is a recognized cause of hypocalcemia?

Low parathyroid hormone levels are a classic cause of hypocalcemia. Parathyroid hormone normally raises calcium by stimulating bone resorption, increasing renal calcium reabsorption, and promoting production of active vitamin D to boost intestinal calcium absorption. When PTH is deficient, these processes slow down: calcium moves less from bone to blood, the kidneys waste less calcium, and the gut absorbs less calcium due to reduced active vitamin D. At the same time, phosphate clearance falls, leading to hyperphosphatemia; the combined effect is a lower serum calcium level. Clinically, hypoparathyroidism often follows thyroid or neck surgery, autoimmune destruction, or infiltrative diseases. For contrast, hyperparathyroidism would raise calcium, not lower it. Hypermagnesemia can cause hypocalcemia by suppressing PTH and causing resistance to PTH, but the direct, classic cause among these choices is loss of PTH production. Hypercalcemia is the opposite scenario and would not cause hypocalcemia.

Low parathyroid hormone levels are a classic cause of hypocalcemia. Parathyroid hormone normally raises calcium by stimulating bone resorption, increasing renal calcium reabsorption, and promoting production of active vitamin D to boost intestinal calcium absorption. When PTH is deficient, these processes slow down: calcium moves less from bone to blood, the kidneys waste less calcium, and the gut absorbs less calcium due to reduced active vitamin D. At the same time, phosphate clearance falls, leading to hyperphosphatemia; the combined effect is a lower serum calcium level.

Clinically, hypoparathyroidism often follows thyroid or neck surgery, autoimmune destruction, or infiltrative diseases.

For contrast, hyperparathyroidism would raise calcium, not lower it. Hypermagnesemia can cause hypocalcemia by suppressing PTH and causing resistance to PTH, but the direct, classic cause among these choices is loss of PTH production. Hypercalcemia is the opposite scenario and would not cause hypocalcemia.

More practice questions