Under what condition might daily, moderate consumption of cooked bok choy pose a risk to thyroid function?

In people with pre-existing iodine deficiency.

Bok choy is classified as a cruciferous vegetable and contains goitrogens, which are substances capable of potentially disrupting the thyroid gland's ability to absorb iodine. This interference can lead to thyroid issues, particularly for individuals who already have an insufficient intake of iodine. The risk associated with goitrogens is largely mitigated in two ways: cooking significantly deactivates these compounds, and having adequate iodine intake in the general diet provides the thyroid with enough resources to overcome mild competitive inhibition. Therefore, the concern arises primarily when iodine levels are already low, even with moderate consumption of the cooked vegetable.