**Core Concept**
Iron deficiency is a common complication in pregnancy, especially during the second trimester, due to increased demand for iron from the growing fetus. Adequate dietary intake is crucial to prevent iron deficiency anemia.

**Why the Correct Answer is Right**
The recommended daily intake of iron during pregnancy is 27 mg, which can be achieved through a balanced diet rich in iron-fortified cereals, lean meats, and dark leafy vegetables. Iron from animal sources (heme iron) is more easily absorbed than iron from plant sources (non-heme iron). Vitamin C can enhance the absorption of non-heme iron.

**Why Each Wrong Option is Incorrect**
**Option A:** Folic acid is essential for preventing neural tube defects, but it does not address the patient's iron deficiency anemia.
**Option B:** Calcium is important for fetal bone development, but it does not directly address the patient's iron deficiency anemia.
**Option C:** Fiber can help regulate bowel movements and prevent constipation, but excessive fiber intake can interfere with iron absorption.

**Clinical Pearl / High-Yield Fact**
Iron deficiency anemia is a leading cause of maternal and fetal morbidity. Pregnant women should consume iron-rich foods or supplements to maintain adequate iron levels, especially during the second and third trimesters.

**Correct Answer:** D. Increase dietary intake of iron-rich foods and consider supplements if necessary.