Iodine occurs in human body as

Options

A. Thyroxine
B. Inorganic iodide
C. Protein bound iodine
D. All the above.

Answer

**Step-by-Step Solution:**

1. **Understanding Iodine's Role in the Human Body:**
- Iodine is an essential trace element that is crucial for the production of thyroid hormones. It is primarily found in the thyroid gland.

2. **Thyroxine Production:**
- The thyroid gland synthesizes the hormone thyroxine (T4) from iodine. Thyroxine plays a vital role in regulating metabolism in the body.

3. **Deficiency of Thyroxine:**
- A deficiency in thyroxine can lead to conditions such as myxedema in adults, which is characterized by symptoms like fatigue, weight gain, and sensitivity to cold.

4. **Inorganic Iodine:**
- Iodine can also exist in the body as inorganic iodides. These are salts that are soluble in water and are essential for the synthesis of thyroid hormones.

5. **Protein Bound Iodine:**
- Iodine can bind to amino acids, particularly tyrosine, to form protein-bound iodine. This is part of the process of creating thyroid hormones.

6. **Conclusion:**
- Therefore, iodine occurs in the human body in three forms: as thyroxine, as inorganic iodide, and as protein-bound iodine. The correct answer to the question is "all the above."

**Final Answer:**
Iodine occurs in the human body as thyroxine, inorganic iodine, and protein-bound iodine. Thus, the correct option is "all the above."

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