Boost Iron Levels: Take Supplements Every Other Day?
Quick Summary: A new study suggests that taking iron supplements every other day might help your body absorb more iron than taking them daily. It also found that taking your dose all at once in the morning is as effective as splitting it up.
Iron Absorption: Why Timing Matters
This research looked at how often and when you take iron supplements affects how well your body uses them. The study found that:
- Taking iron every other day led to better iron absorption compared to taking it daily.
- Taking one dose in the morning worked just as well as splitting the dose into two.
Study Details
- Who was studied: 60 women who had low iron levels but weren't severely anemic (lacking enough red blood cells).
- How long: The first part of the study lasted up to 28 days. The second part lasted 3 days.
- What they took: Participants took iron supplements (60 mg of elemental iron). Some took it daily, some every other day, some once a day, and some twice a day.
What This Means For You
If you take iron supplements, this research suggests:
- Consider taking your iron every other day. This might help your body absorb more iron.
- Take your dose in the morning. It's just as effective as splitting the dose.
- Talk to your doctor. Before changing how you take your iron supplements, it's always best to get advice from your healthcare provider. They can help you figure out the best plan for your specific needs.
Study Limitations
- Small Study: The study involved a relatively small number of women.
- Not for Everyone: The study focused on women with low iron, not those with anemia (severe iron deficiency).
- More Research Needed: The researchers say more studies are needed, especially in people with anemia, to confirm these findings.
Technical Analysis Details
Key Findings
Alternate-day iron dosing significantly increased fractional iron absorption (21.8% vs 16.3%; p=0.0013) and total iron absorption (175.3 mg vs 131.0 mg; p=0.0010) compared to consecutive-day dosing over equivalent total iron exposure periods. Single morning dosing showed no significant difference in absorption versus twice-daily split dosing (fractional: 11.8% vs 13.1%, p=0.33; total: 44.3 mg vs 49.4 mg, p=0.33). Consecutive-day dosing and split dosing both elevated serum hepcidin (p=0.0031 and p=0.013 respectively), indicating hepcidin-mediated suppression of absorption with more frequent dosing.
Study Design
Two prospective, open-label, randomized controlled trials conducted in 2015. Study 1 compared consecutive-day (n=21) versus alternate-day dosing (n=19) over 14 vs 28 days in iron-depleted women. Study 2 compared once-daily (n=10) versus twice-daily dosing (n=10) over 3 days in similar participants. Iron absorption was measured using stable iron isotopes (⁵⁷Fe/⁵⁸Fe). Total participants: 60 non-anemic, iron-depleted women.
Dosage & Administration
Participants received 60 mg elemental iron as ferrous sulfate. Study 1: Consecutive-day group took 60 mg daily for 14 days; alternate-day group took 60 mg every other day for 28 days (total 14 doses). Study 2: Once-daily group took 60 mg as a single morning dose; twice-daily group took 30 mg twice daily (morning and evening) for 3 days.
Results & Efficacy
Alternate-day dosing increased fractional absorption by 33.7% (geometric mean 21.8% [95% CI: 13.7, 34.6] vs 16.3% [9.3, 28.8]; p=0.0013) and total absorbed iron by 33.8% (175.3 mg [110.3, 278.5] vs 131.0 mg [71.4, 240.5]; p=0.0010). Hepcidin was significantly higher during consecutive-day dosing (p=0.0031). Split dosing showed no absorption benefit but increased hepcidin versus single dosing (p=0.013). No severe adverse events occurred.
Limitations
Small sample size (max n=21 per group), short duration (≤28 days), and exclusive focus on non-anemic, iron-depleted women limit generalizability to iron-deficiency anemia patients. Open-label design risks bias. Hepcidin measurements were limited to early supplementation phases. Authors explicitly state findings require validation in anemic populations.
Clinical Relevance
For non-anemic individuals with iron depletion, alternate-day dosing (e.g., 60 mg every other morning) may optimize iron absorption by minimizing hepcidin elevation, potentially improving efficacy and reducing required treatment duration. Single daily doses appear equally effective as split doses while simplifying regimens. These findings challenge current guidelines recommending daily/split dosing but require confirmation in anemic patients before clinical adoption. Users should consult healthcare providers before altering iron regimens.
Original Study Reference
Iron absorption from oral iron supplements given on consecutive versus alternate days and as single morning doses versus twice-daily split dosing in iron-depleted women: two open-label, randomised controlled trials.
Source: PubMed
Published: 2017
📄 Read Full Study (PMID: 29032957)
