IronNEW2026-10

Reduced-dose alternate-day oral iron supplementation in women with iron deficiency: a randomized controlled trial.

Valerii Maria Chiara, Dussias Nikolas Kostantine, Perri Anna, Spigarelli Renato et al. — European journal of nutrition

Summary

This study investigated a new way to take iron supplements for women with low iron levels. It found that taking a lower dose of iron every other day was just as effective at improving iron status as taking a standard dose daily. This approach could help reduce common side effects and make iron supplementation easier to stick with.

AI-generated summary — read the original

Key points

Taking iron supplements every other day with a lower dose can be as effective as daily intake for improving iron levels.
This alternate-day approach may help reduce common digestive side effects associated with iron supplements.
The study suggests that less frequent, lower-dose iron supplementation could be a good option for women with iron deficiency.
Both daily and alternate-day iron regimens were well-tolerated by participants.

What the study looked at

**What question did the study ask?** This research aimed to determine if taking a lower dose of iron supplements every other day could effectively improve iron levels in women with iron deficiency, similar to or better than taking a standard daily dose. The goal was to find a strategy that might reduce common side effects and improve absorption. **How was it studied?** Sixty-six women of reproductive age (18-50 years) with diagnosed iron deficiency participated in this randomized controlled trial. They were divided into two groups for 42 days: one group received a smaller dose of iron every other day along with a gut health supplement, and the other group received a standard daily dose of iron. Researchers measured their iron levels, including ferritin (a key indicator of iron stores), before and after the study. **What did it find?** The study found that both groups experienced significant and comparable improvements in their iron stores, as measured by ferritin levels. There was no significant difference in effectiveness between taking a lower dose every other day and taking a standard dose daily, even though the alternate-day group received less total iron. Both methods were generally well-tolerated, with only minor temporary digestive issues reported.

Dietary takeaway

For individuals, especially women, struggling with iron deficiency, this study suggests that taking iron supplements every other day at a reduced dose could be a viable and potentially more tolerable option than daily intake. While promising, remember that this is just one study, and individual needs vary. Always consult with a healthcare professional before making changes to your supplement regimen to ensure it's appropriate for your specific health situation.

Abstract

PURPOSE: Oral iron supplementation is frequently limited by gastrointestinal side effects and reduced absorption associated with hepcidin-mediated regulation. This randomized, parallel-group, active-controlled study evaluated whether a reduced-dose alternate-day oral iron supplementation strategy could improve iron status in women with iron deficiency. METHODS: Sixty-six iron-deficient women of reproductive age (18-50 years; serum ferritin < 30 ng/mL) were randomized to receive, for 42 days, either micronized, dispersible ferric pyrophosphate providing 21 mg of elemental iron every 48 h combined with a daily gut microbiota modulator, or sucrosomial ferric pyrophosphate providing 30 mg of elemental iron per day. The primary endpoint was serum ferritin, while secondary endpoints included serum iron, transferrin, transferrin saturation (TSAT), total iron-binding capacity (TIBC), hemoglobin, and red blood cell count. RESULTS: Serum ferritin increased significantly over time in both groups (p < 0.001), with no significant differences between treatments. Comparable improvements were observed for serum iron, transferrin, TSAT, and TIBC, while hemoglobin remained stable throughout the study. Both interventions were generally well tolerated, with only mild transient gastrointestinal adverse events and no clinically relevant changes in inflammatory markers. CONCLUSION: A reduced-dose alternate-day oral iron supplementation strategy achieved improvements in iron status comparable to standard daily supplementation despite lower cumulative iron exposure. These findings support the potential clinical relevance of physiologically informed low-dose iron supplementation strategies in women with iron deficiency.

View on PubMed →DOI: 10.1007/s00394-026-04139-9