Final answer:
The nurse should advise clients to avoid calcium supplements while taking iron, as they may interfere with iron absorption. Adequate iron intake is crucial during pregnancy for the health of both the mother and the developing fetus.
Step-by-step explanation:
The nurse should instruct the clients to avoid taking calcium supplements with iron. The absorption of iron can be inhibited when calcium and iron are taken together, as they can compete for the same absorption pathways in the body. To maximize the effectiveness of iron absorption it is recommended to separate the intake of iron and calcium supplements by several hours. Pregnant women have increased nutritional needs, including a higher requirement for iron to support the development of the fetus and increased blood volume. It is essential to provide adequate micronutrients, such as iron, folate, and vitamin D, to ensure both maternal health and fetal development.