**Core Concept**
Iodine is an essential micronutrient required for thyroid hormone production, particularly during lactation when it is crucial for the development of the infant's thyroid gland. The iodine requirement during lactation is higher than during pregnancy due to the increased demand for thyroid hormones in the infant.

**Why the Correct Answer is Right**
The correct answer is 250-300 μg/day, which is the recommended daily iodine intake for lactating women. This increased requirement is due to the transfer of iodine from the mother's bloodstream to the breast milk, which is essential for the infant's growth and development. The thyroid gland uses iodine to synthesize thyroid hormones, which are vital for the regulation of metabolism, growth, and development.

**Why Each Wrong Option is Incorrect**
* **Option A:** 150 μg/day is the recommended daily iodine intake for non-pregnant and non-lactating women, which is not sufficient for lactating women.
* **Option B:** 500 μg/day is excessive and may lead to iodine toxicity, which can cause thyroid dysfunction and other health problems.
* **Option C:** There is no specific recommendation for the iodine requirement during lactation as 250-300 μg/day.

**Clinical Pearl / High-Yield Fact**
Lactating women with inadequate iodine intake may experience thyroid dysfunction, which can affect the development of the infant's brain and nervous system. Therefore, it is essential for lactating women to consume iodized salt and other iodine-rich foods to meet their increased iodine requirements.

**Correct Answer: D. 250-300 μg/day**