**Core Concept**
High calcium intake has a significant impact on various physiological processes, particularly bone metabolism and kidney function. Calcium homeostasis is tightly regulated by hormonal mechanisms, involving parathyroid hormone (PTH), vitamin D, and calcitonin.

**Why the Correct Answer is Right**
High calcium intake can lead to hypercalcemia, a condition characterized by elevated serum calcium levels. When calcium levels exceed the body's needs, the parathyroid glands release PTH, which acts on the kidneys to increase calcium reabsorption and promote bone resorption. This results in an increase in serum calcium levels, which can lead to various clinical manifestations, including nephrocalcinosis, renal stones, and cardiovascular effects.

**Why Each Wrong Option is Incorrect**
**Option A:** This is a vague term and does not accurately describe the effects of high calcium intake.
**Option B:** While high calcium intake can lead to hypercalcemia, this option is too broad and does not specify the underlying mechanism.
**Option C:** This option is incorrect as high calcium intake does not directly lead to hypocalcemia.

**Clinical Pearl / High-Yield Fact**
It is essential to note that high calcium intake can have varying effects on individuals, particularly those with pre-existing kidney disease or vitamin D deficiency. Regular monitoring of serum calcium levels and kidney function is crucial in patients with high calcium intake.

**Correct Answer: C. Hypercalcemia.**