**Core Concept**
Metastatic calcification is a type of calcification that occurs in previously normal tissues due to elevated blood levels of calcium, often as a result of hypercalcemia caused by hyperparathyroidism, vitamin D toxicity, or other conditions that lead to increased bone resorption.

**Why the Correct Answer is Right**
Metastatic calcification typically affects the kidneys, lungs, and gastrointestinal tract, and is mediated by the enzyme alkaline phosphatase, which catalyzes the deposition of calcium phosphate crystals in tissues. This process is often seen in conditions characterized by hypercalcemia, where the elevated calcium levels exceed the solubility limits of calcium salts, leading to precipitation in tissues.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not typically associated with metastatic calcification.
**Option B:** While calcification can occur in this condition, it is more commonly associated with dystrophic calcification.
**Option C:** This option is a potential cause of metastatic calcification, but is not the most common scenario.

**Clinical Pearl / High-Yield Fact**
Notably, metastatic calcification often presents as a radiographic finding, and is a key differentiator from dystrophic calcification, which occurs in damaged or necrotic tissues.

**Correct Answer:** D.