Iron supplement prescription
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Iron Supplement Prescription: Insights from Recent Research
Efficacy of Vitamin C with Iron Supplementation
Vitamin C and Iron Absorption
Vitamin C is often prescribed alongside iron supplements to enhance iron absorption by converting ferric iron (Fe3+) to its more absorbable ferrous form (Fe2+). A systematic review and meta-analysis found that adding vitamin C to iron supplementation resulted in a small but statistically significant increase in serum hemoglobin (0.14 g/dL) and serum ferritin levels (3.23 µg/L) compared to iron alone. However, the clinical relevance of these increases remains uncertain 1.
Adverse Effects
The addition of vitamin C did not significantly alter the incidence of adverse effects such as constipation, nausea, or vomiting. Interestingly, the risk of gastrointestinal upset was lower in the iron plus vitamin C group 1.
Iron Supplementation Practices in Different Regions
Switzerland vs. UK
A study comparing iron supplementation practices in Switzerland and the UK revealed that iron supplementation is more prevalent in Switzerland (9.4%) compared to the UK (4.4%). Parenteral iron administration was significantly higher in Switzerland. Ferritin tests were more frequently conducted before iron prescription in Switzerland, whereas hemoglobin tests were more common in the UK 2.
Intermittent vs. Daily Iron Supplementation
Menstruating Women
Intermittent iron supplementation (one to three times a week) has been suggested as a safer alternative to daily supplementation due to fewer side effects. Studies show that intermittent supplementation is effective in reducing anemia and improving hemoglobin and ferritin levels, although it is less effective than daily supplementation in preventing anemia 39.
Pregnancy
Daily iron supplementation during pregnancy is effective in reducing the risk of low birthweight and preventing maternal anemia and iron deficiency. However, it is associated with higher hemoglobin concentrations, which may pose risks. The side effects of daily supplementation, such as gastrointestinal issues, are also a concern 57.
Optimizing Iron Absorption
Dosing Regimens
Research indicates that providing iron supplements on alternate days and in single doses optimizes iron absorption better than daily split doses. This approach reduces serum hepcidin levels, which can inhibit iron absorption 4.
Chemical Forms of Iron in Supplements
Prenatal Supplements
The chemical form of iron in supplements affects its bioavailability. Ferrous fumarate is commonly used in commercial prenatal supplements, whereas ferrous sulfate is often used in clinical trials. This discrepancy may have clinical implications, suggesting a need for standardization in the forms of iron used in supplements and clinical trials 6.
Conclusion
Iron supplementation practices vary widely, and the choice of regimen and formulation can significantly impact efficacy and side effects. While adding vitamin C to iron supplements shows some benefits, its clinical significance is debatable. Intermittent supplementation offers a safer alternative to daily dosing, particularly for menstruating women, but may be less effective in preventing anemia. Optimizing dosing regimens and standardizing the chemical forms of iron in supplements could enhance the effectiveness of iron supplementation programs.
Sources and full results
Most relevant research papers on this topic
Efficacy of Vitamin C with Iron Supplementation in Iron Deficiency Anemia Patients: A Systematic Review and Meta-Analysis
Oral iron supplementation with vitamin C may slightly improve hemoglobin levels and ferritin levels in patients with iron deficiency anemia, but does not significantly differ in adverse effects.
Meta-AnalysisIron supplementation in Switzerland - A bi-national, descriptive and observational study.
Iron supplementation is more common in Switzerland than in the UK, particularly for parenteral iron therapy, with relatively infrequent haemoglobin measurements prior to new therapy.
Observational StudyIntermittent iron supplementation for reducing anaemia and its associated impairments in adolescent and adult menstruating women.
Intermittent iron supplementation effectively reduces anaemia risk and improves haemoglobin concentration in menstruating women compared to no intervention or a placebo.
Meta-Analysis
Very Rigorous Journal
Highly CitedIron 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.
Oral iron supplements given alternate days and as single morning doses have better iron absorption than those given daily or split doses in iron-depleted women.
RCTHighly CitedDaily oral iron supplementation during pregnancy.
Daily oral iron supplementation during pregnancy reduces the risk of low birthweight newborns, maternal anaemia, and iron deficiency, but may increase the risk of side effects.
Meta-AnalysisVery Rigorous JournalHighly CitedThe Chemical Forms of Iron in Commercial Prenatal Supplements Are Not Always the Same as Those Tested in Clinical Trials.
The chemical forms of iron in commercial prenatal supplements are not always the same as those tested in clinical trials, which may have clinical implications.
Systematic ReviewVery Rigorous JournalDaily oral iron supplementation during pregnancy.
Daily oral iron supplementation during pregnancy reduces maternal anaemia at term and iron-deficiency anaemia, but may increase the risk of iron-rich blood.
Meta-AnalysisVery Rigorous JournalHighly CitedIron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance
Dietary iron interventions, such as iron-rich diets and haem iron-based diets, can help maintain iron status in female athletes and potentially improve their sports and exercise performance.
Literature ReviewVery Rigorous JournalHighly CitedIntermittent iron supplementation for reducing anaemia and its associated impairments in menstruating women.
Intermittent iron supplementation effectively reduces anaemia risk and improves haemoglobin and ferritin levels in menstruating women, but may have less impact on overall health compared to daily supplementation.
Meta-AnalysisVery Rigorous JournalHighly CitedEffects of long-term weekly iron and folic acid supplementation on lower genital tract infection – a double blind, randomised controlled trial in Burkina Faso
Weekly iron supplementation in young women does not increase the risk of lower genital tract infections but may increase general morbidity due to unabsorbed gut iron due to malaria.
RCT
Large Human Trial
Rigorous Journal