A nurse is caring for a client with iron-deficiency anemia. Which nursing intervention should be prioritized to optimize iron absorption?

Vitamin C enhances iron absorption by converting ferric iron to ferrous iron, which is more readily absorbed. Other options (milk, coffee/tea) contain substances that inhibit absorption.

Understanding Iron Absorption in Iron-Deficiency Anemia

The core principle guiding this intervention is the significant impact of dietary timing and co-factors on the bioavailability of oral iron. The provided evidence directly demonstrates that food intake immediately before iron administration substantially reduces absorption. Therefore, the priority is to identify the strategy that actively enhances absorption to correct the deficiency efficiently.

Analysis of the Correct Answer

Option 3 is correct. Vitamin C (ascorbic acid) is a potent enhancer of non-heme iron absorption, which is the form found in most oral supplements and plant-based foods. It acts by reducing ferric iron (Fe³⁺) to the more soluble and absorbable ferrous form (Fe²⁺) in the duodenum's alkaline environment, preventing it from forming insoluble complexes. This chemical reduction keeps the iron soluble and available for uptake by enterocytes. The study by Komatsu et al. (2026) reinforces the critical need to maximize absorption by showing how easily it is compromised by other factors, making the proactive use of an enhancer like vitamin C a clinical priority ^[1].

Analysis of Incorrect Answers

Option 1: Administering iron with milk is contraindicated. Milk contains calcium and casein phosphopeptides, which are potent inhibitors of iron absorption. Calcium competes with iron for the divalent metal transporter 1 (DMT1) on the apical membrane of enterocytes, directly blocking its uptake. This would further reduce the already limited absorption.

Option 2: Coffee and tea contain polyphenols, specifically tannins, which form insoluble, non-absorbable complexes with iron in the gastrointestinal lumen. This chelation effect is a powerful inhibitor of absorption and would directly counteract the therapeutic goal of the supplement.

Option 4: This is the most critical distractor and is directly refuted by the provided evidence. The study by Komatsu et al. (2026) found that iron absorption after administering an oral iron preparation "following a meal is generally reduced compared with fasting" ^[1]. The research specifically investigated administration under fed conditions (immediately after a meal) and confirmed a reduction in absorption. For optimal absorption, oral iron is best administered on an empty stomach, typically one hour before or two hours after a meal, unless significant gastrointestinal intolerance occurs. The study's finding that food impairs absorption makes this option the opposite of the correct priority.