Which of the following laboratory results is consistent with primary hypoparathyroidism?

In primary hypoparathyroidism, the parathyroid glands fail to produce adequate parathyroid hormone (PTH), which is essential for regulating calcium and phosphorus levels in the body. A hallmark of this condition is the manifestation of low serum calcium levels due to insufficient PTH, leading to impaired mobilization of calcium from bones and reabsorption in the kidneys.

Concurrently, the high levels of inorganic phosphorus (Pi) arise because PTH typically promotes the excretion of phosphate in the kidneys. Without sufficient PTH, renal excretion of phosphate is reduced, resulting in elevated phosphate levels in the serum.

Therefore, the combination of low calcium and high inorganic phosphorus is characteristic of primary hypoparathyroidism, aligning consistently with the physiological disturbances caused by inadequate parathyroid hormone activity.