In chronic kidney disease, which electrolyte disturbance and bone-mineral disorder commonly occur due to dysregulated phosphate and parathyroid hormone?

• A. Hyperphosphatemia with hypocalcemia leading to secondary hyperparathyroidism and bone disease
• B. Hyperphosphatemia with hypercalcemia
• C. Hyperkalemia with acidosis
• D. Hyponatremia with hypocalcemia

Answer: (A)

In chronic kidney disease, the kidneys struggle to excrete phosphate and to activate vitamin D, which leads to phosphate retention and reduced calcium absorption. The result is hyperphosphatemia and hypocalcemia. The falling calcium levels stimulate the parathyroid glands to release more parathyroid hormone, causing secondary hyperparathyroidism. Elevated PTH drives bone turnover and mineral remodeling, producing renal osteodystrophy, the bone-mineral disorder associated with CKD. This combination—high phosphate with low calcium triggering secondary hyperparathyroidism and bone disease—best fits the pattern described.