Iron Supplementation Guidelines for Adults with Iron Deficiency Anemia

Introduction to Iron Supplementation

The American Gastroenterological Association recommends taking 50-100 mg of elemental iron once daily in the morning on an empty stomach, using ferrous sulfate as the first-line formulation, for a 35-year-old woman with iron deficiency anemia 1, 2

The British National Formulary suggests ferrous sulfate 200 mg tablets (containing 65 mg elemental iron) taken once daily as the most cost-effective option 1, 2
Alternative formulations if ferrous sulfate is not tolerated include ferrous fumarate 210-322 mg tablets (69-106 mg elemental iron) 1, 2

The National Institute of Nutrition recommends taking iron with 250-500 mg vitamin C (ascorbic acid) to enhance iron absorption 3, 4, 2
Avoid taking iron with tea, coffee, or calcium-containing foods/supplements, which inhibit absorption 2

Expect hemoglobin to increase by at least 10 g/L (1 g/dL) within 2 weeks if treatment is effective, according to the American College of Gastroenterology 1, 2
If hemoglobin does not rise by at least 10 g/L after 2 weeks of daily oral iron, this strongly predicts treatment failure (sensitivity 90.1%, specificity 79.3%), as reported by the Gut journal 1

Do not take multiple doses per day, as this increases side effects without improving absorption due to hepcidin elevation that persists 24 hours after each dose, as stated by the British National Formulary 1, 2
Avoid modified-release preparations, considered "less suitable for prescribing" according to the British National Formulary 1, 2
Do not rely on multivitamins as they contain insufficient elemental iron (typically ≤14 mg) for treating anemia, as recommended by the American College of Gastroenterology 1, 2