Final answer:
Pregnant clients with iron deficiency anemia should take iron supplements with meals to enhance absorption.
Step-by-step explanation:
The RN should advise the pregnant client to take iron supplements with meals to enhance absorption. Iron supplements should not be taken with a glass of milk because calcium can interfere with iron absorption. Taking iron supplements on an empty stomach is not recommended because it may cause gastrointestinal discomfort. If constipation occurs, the client should not discontinue iron supplements, but rather increase fluid and fiber intake or speak to their healthcare provider for additional recommendations.