Abnormalities of bone metabolism is associated with excess of which vitamins -a) Vitamin Ab) Thiaminec) Vitamin Dd) Tocoferol

**Core Concept**
Excessive intake of certain vitamins can disrupt normal bone metabolism, leading to various disorders. This question requires understanding of vitamin excess and its effects on bone health.

**Why the Correct Answer is Right**
Vitamin A toxicity is known to cause abnormalities in bone metabolism. High levels of vitamin A can lead to increased bone resorption, resulting in osteoporosis and bone pain. This is due to the inhibition of osteoblast function and increased osteoclast activity. Vitamin A also affects the regulation of calcium and phosphorus metabolism, further contributing to bone abnormalities.

**Why Each Wrong Option is Incorrect**
**Option A:** Vitamin A is the correct answer, but Vitamin Ab is not a valid option.
**Option B:** Thiamine is a B-complex vitamin essential for carbohydrate metabolism, but it is not directly associated with bone metabolism.
**Option C:** Vitamin D is crucial for calcium absorption and bone mineralization, but excess vitamin D can lead to hypercalcemia, not abnormalities in bone metabolism.
**Option D:** Tocopherol is another term for Vitamin E, which is primarily involved in antioxidant functions and is not directly linked to bone metabolism.

**Clinical Pearl / High-Yield Fact**
It's essential to note that excessive intake of fat-soluble vitamins, including Vitamin A, can lead to toxicity, which may manifest as bone abnormalities. This emphasizes the importance of monitoring vitamin intake and maintaining a balanced diet.

**Correct Answer:** C. Vitamin D