**Core Concept**
Excessive intake of certain vitamins can lead to bony abnormalities due to their impact on bone metabolism and mineralization. Hypervitaminosis refers to the condition of having an excessive amount of a particular vitamin in the body, which can cause various health problems.

**Why the Correct Answer is Right**
Vitamin A is a fat-soluble vitamin that plays a crucial role in bone health. However, excessive intake of Vitamin A can lead to hypervitaminosis A, which causes an accumulation of retinoic acid in the body. This can disrupt bone metabolism, leading to bony abnormalities such as osteoporosis, osteopenia, and increased risk of fractures. The mechanism involves the inhibition of osteoblasts, which are responsible for bone formation, and the stimulation of osteoclasts, which are responsible for bone resorption.

**Why Each Wrong Option is Incorrect**
**Option B:** Vitamin D is also a fat-soluble vitamin that plays a crucial role in bone health by regulating calcium levels and promoting bone mineralization. However, hypervitaminosis D is less likely to cause bony abnormalities compared to Vitamin A, as it primarily affects calcium metabolism.
**Option C:** Vitamin C is a water-soluble vitamin that is essential for collagen synthesis and iron absorption. Hypervitaminosis C is not typically associated with bony abnormalities.
**Option D:** Vitamin E is a fat-soluble vitamin that acts as an antioxidant in the body. Hypervitaminosis E is not typically associated with bony abnormalities.
**Option E:** Vitamin K is a fat-soluble vitamin that plays a crucial role in blood clotting and bone health by regulating osteoclast activity. Hypervitaminosis K is not typically associated with bony abnormalities.

**Clinical Pearl / High-Yield Fact**
It is essential to note that excessive intake of Vitamin A can also cause other health problems, such as headaches, dizziness, and liver damage. Therefore, it is crucial to monitor Vitamin A levels and ensure adequate intake to prevent hypervitaminosis A.

**Correct Answer:** A. Vitamin A.