Question 1

What does the Ganzoni formula account for?

Accepted Answer

The Ganzoni formula calculates two components: the iron needed to raise hemoglobin to the target level (based on body weight and hemoglobin deficit) and the iron needed to replenish depleted storage pools (approximately 500 mg for adults). The factor 2.4 derives from the iron content per gram of hemoglobin (3.4 mg) multiplied by the estimated blood volume (approximately 70 mL/kg), converting to the mg of iron needed per g/dL hemoglobin increase per kg body weight.

Question 2

Why is every-other-day dosing sometimes recommended?

Accepted Answer

Research published in The Lancet and Blood journal showed that oral iron triggers release of hepcidin, a hormone that blocks iron absorption from the gut for approximately 24 hours. Taking iron daily means the second-day dose is poorly absorbed. Studies found that every-other-day dosing of 65 mg elemental iron resulted in similar or better total iron absorption compared to daily dosing, with fewer gastrointestinal side effects. This approach may be preferred for mild-moderate deficiency.

Question 3

When is IV iron preferred over oral iron?

Accepted Answer

Intravenous iron is preferred when: oral iron is not tolerated due to severe GI side effects, the patient has malabsorption conditions (celiac disease, inflammatory bowel disease, post-gastric bypass), the iron deficit is very large (>1500 mg), rapid correction is needed (severe anemia, upcoming surgery), or the patient is on hemodialysis. Modern IV iron formulations (ferric carboxymaltose, iron sucrose) are generally safe and can deliver large doses in a single infusion.

Question 4

What foods help with iron absorption?

Accepted Answer

Vitamin C significantly enhances non-heme iron absorption. Consuming citrus fruits, bell peppers, tomatoes, or strawberries with iron-rich foods or supplements can double or triple absorption. Conversely, calcium, tannins (tea, coffee), phytates (whole grains, legumes), and antacids inhibit iron absorption. When taking iron supplements, avoid dairy products, tea, and coffee within 2 hours. Heme iron from meat is absorbed 2-3 times more efficiently than plant-based non-heme iron.

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