Why has a healthcare provider likely prescribed iron tablets to a woman attending antepartum classes?

Iron tablets are commonly prescribed to pregnant women primarily because it's often challenging to obtain adequate iron through diet alone during this crucial time. Pregnancy increases the body's demand for iron due to the growing fetus, which requires iron for its development, as well as the increased blood volume of the mother.

While many foods contain iron, the additional needs during pregnancy may not be fully met just through diet, especially in populations where dietary sources of iron are limited or if the mother has dietary restrictions. Supplementing with iron tablets helps ensure that these increased iron requirements are met, reducing the risk of iron deficiency anemia, which can lead to complications for both the mother and the baby.

The other options, while addressing various aspects of iron metabolism and needs, do not capture the primary reason for supplementation during pregnancy as effectively as the correct choice.