**Core Concept**
Hypercalciuria refers to the excessive excretion of calcium in the urine, which can increase the risk of kidney stones and other complications. This condition often results from an imbalance in calcium and vitamin D metabolism, leading to an elevated level of calcium in the blood.

**Why the Correct Answer is Right**
Hypercalciuria can be caused by several factors, including primary hyperparathyroidism, a condition characterized by the overproduction of parathyroid hormone (PTH), which stimulates the release of calcium from bones into the bloodstream and increases its absorption from the intestine. This results in elevated levels of calcium in the blood and, subsequently, in the urine. Vitamin D intoxication also leads to hypercalciuria by increasing the absorption of calcium from the intestine. Furthermore, sarcoidosis, a systemic granulomatous disease, can cause hypercalcemia due to increased production of 1,25-dihydroxyvitamin D, a potent form of vitamin D that enhances calcium absorption.

**Why Each Wrong Option is Incorrect**
**Option A:** Hyperparathyroidism is a correct cause of hypercalciuria, so this option is not incorrect.
**Option B:** Vitamin D intoxication is also a correct cause of hypercalciuria, so this option is not incorrect.
**Option C:** Sarcoidosis is a correct cause of hypercalciuria, so this option is not incorrect.

**Clinical Pearl / High-Yield Fact**
It is essential to note that hypercalciuria can also be caused by other conditions such as thiazide diuretics, which can increase calcium reabsorption in the kidneys, and certain types of kidney stones, such as calcium oxalate stones. A thorough evaluation of a patient with hypercalciuria should include a review of their medical history, laboratory results, and imaging studies to identify the underlying cause.

✓ Correct Answer: D. All