Which element is commonly added to table salt for public health purposes?

The addition of iodine to table salt is a public health measure aimed at preventing iodine deficiency disorders, which can lead to serious health issues such as goiter and cognitive impairments. Iodine is an essential nutrient that the human body needs for the production of thyroid hormones, which are crucial for regulating metabolism, growth, and development.

Historically, iodine deficiency was common in many areas, particularly inland regions where seafood, a natural source of iodine, was not readily available. The fortification of table salt with iodine was introduced in the early 20th century as a simple and effective way to ensure adequate iodine intake in the general population. By making iodized salt widely available, public health agencies have significantly reduced the prevalence of iodine deficiency and its associated health issues.

Other options, such as calcium and potassium, do serve important functions in nutrition but are not primarily added to table salt for public health reasons. Sodium, on the other hand, is the main component of salt, but it does not address the specific health concerns related to iodine deficiency. Therefore, iodine is the correct answer, as it directly relates to public health initiatives focused on preventing deficiency-related health risks.