American Board of Internal Medicine (ABIM) Certification Practice Exam

What should be the daily vitamin and mineral supplement for a patient with iron deficiency?

1. Ferrous sulfate 500 mg

2. Ferrous sulfate 325 mg

3. Delayed-release iron supplement

4. IV iron therapy

The correct answer is: Ferrous sulfate 325 mg

In cases of iron deficiency, ferrous sulfate is commonly recommended as a supplement to restore iron levels in the body. The dosage of 325 mg is significant because it is typically the amount that, when administered as ferrous sulfate, provides an effective dose of elemental iron (which is about 65 mg per tablet). This dosage is generally well tolerated and is sufficient for the majority of patients to replenish their iron stores while minimizing gastrointestinal side effects that can occur with higher doses. Other formulations of iron, like delayed-release supplements or intravenous therapy, may be indicated in certain clinical scenarios, such as for patients who cannot tolerate oral iron or have malabsorption issues. However, for standard management of iron deficiency, especially when initiating therapy or in cases where oral supplementation is suitable, the 325 mg dose of ferrous sulfate stands out as the most widely accepted and accessible option for daily supplementation. It's important to note that higher doses, while sometimes effective, can lead to increased gastrointestinal discomfort, which is why the 325 mg dose is considered optimal for both efficacy and safety in many patients with iron deficiency.