Wir verwenden standardmäßig essenzielle Cookies (Anmeldung, deine gespeicherten Ziele/Stacks). Mit deiner Erlaubnis aktivieren wir außerdem datenschutzfreundliche Analytik (Vercel Web Analytics, anonyme Ladezeit-Metriken) und Fehler-Replay-Diagnostik (Sentry — DOM-Snapshots nur, wenn ein Fehler auftritt), damit wir Bugs schneller beheben können. Mehr über Cookies erfahren
Fe9.0
Iron – Forschung
Hilft wahrscheinlich
809 begutachtete Studien
Was die Evidenz sagt
Hilft vermutlich
Iron half in etwa der Hälfte (9/13) der Studien, die einen Effekt gemessen haben — vielversprechend, aber nicht einhellig.
Die meiste Evidenz stammt aus hochwertigen Meta-Analysen und randomisierten Studien, veröffentlicht 1966–2026 mit einer typischen Studiengröße von 397 Teilnehmenden.
Basierend auf 808 Studien · 135 Meta-Analysen · 606 RCTs · 613,851 Teilnehmende insgesamt
Konfidenz
Hohe Konfidenz
Was die Studien gefunden haben
9geholfen2unklar2nicht geholfen· 795 weitere ohne bewertete Effektdaten
Nach Outcome
Iron deficiency & anemia
Hilft wahrscheinlich598 Studien
Women's healthKann helfen, menstruelle Beschwerden und PMS-Symptome zu reduzieren · 1-3 Zyklen · Liefert essenzielle Nährstoffe für eine gesunde Schwangerschaft · Fortlaufend
Hilft vermutlich173 Studien
Therapeutic & clinical
Hilft vermutlich95 Studien
Kidney & renal health
Überwiegend Mechanismus / Beobachtung46 Studien
Heart & blood pressure
Überwiegend Mechanismus / Beobachtung26 Studien
Cognitive function
Überwiegend Mechanismus / Beobachtung18 Studien
Safety profile
Überwiegend Mechanismus / Beobachtung17 Studien
Endurance & exercise performanceVerbesserte Ausdauer und Erholung bei Mangel · 4-8 Wochen · Stellt VO2max und Ausdauer bei Mangel wieder her · 4-12 Wochen
Überwiegend Mechanismus / Beobachtung15 Studien
Digestive health
Überwiegend Mechanismus / Beobachtung13 Studien
Energy & fatigueDeutliche Verbesserung der Energie bei Mangel · 2-4 Wochen für Symptome; 3-6 Monate zur Auffüllung der Speicher
Hilft wahrscheinlich10 Studien
In Zahlen
Aus 37 Studien mit messbaren Effekten gezogen
Wahrscheinlich echte Effekte
100%
über Studien hinweg
Untersuchte Personen
614k
typische Studie: 397 Personen
Stärkste Designs
741
135 gepoolt, 606 randomisiert
Zeigte Nutzen
69%
9/13 Studien
Wie lange Studien liefen
1–4 Wochen
1
1–3 Monate
2
Untersuchte Populationen
Adults2
General population2
Women1
Pregnant women1
Stetige Forschung
175 Studien in den letzten 5 Jahren · Neueste Meta-Analyse: 2026
196619962026
1Meta-Analysen=7,475 · very large study2026
Einfach gesagt: Iron supplementation may lead to improved blood indices and iron stores, but we are uncertain about the effect due to heterogeneity in the population and different methods and doses of iron supplementation.
Geneen LJ et al. · The Cochrane database of systematic reviews (2026)
Overall, we downgraded the certainty of the evidence primarily for risk of bias, high heterogeneity (between-study inconsistency) that was not explained through subgrouping, and imprecision (wide confidence intervals (CIs)), largely due to very small sample sizes in some studies.
More participants may experience adverse events with oral iron compared to no iron, including abdominal pain, constipation, and diarrhoea (RR 1.69, 95% CI 1.15 to 2.47; 8 studies, 2641 participants), but the evidence is very uncertain.
Serum ferritin may also be higher with IV iron at the first donation since commencement of treatment (MD 78.16, 95% CI 37.20 to 119.12 ng/mL higher; 2 studies, 479 participants), but the evidence is very uncertain.
2Lung cancer riskMeta-Analysen=21,943 · very large study2024
Einfach gesagt: However, a positive association was observed between dietary heme iron and the risk of lung cancer in women, which may require further investigation.
Mohammadzadeh M et al. · International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition (2024)
Spürbar Schaden
← SchlechterKein EffektBesser →
Methods: We searched PubMed, Web of Science, Scopus and Google scholar for eligible articles published through May 2023 reporting the Relative Risk (RR), Hazard Ratio (HR) or Odds Ratio (OR) with 95% confidence interval (95% CI).
There were no significant associations between the highest dietary total iron (heme and non-heme) (RR: 1.09, 95% CI: 0.78 to 1.51) or heme iron (RR: 1.01, 95% CI: 0.73 to 1.38) intake compared to the lowest intake with lung cancer risk.
However, in the subgroup of women (cases n=5074), heme iron was associated with a 14% increase in the risk of lung cancer (RR: 1.14, 95% CI: 1.01 to 1.29).
3Low birthweightMeta-Analysen=48,971 · very large study2024
Einfach gesagt: Daily oral iron supplementation during pregnancy may reduce maternal anaemia and iron deficiency at term.
Finkelstein JL et al. · The Cochrane database of systematic reviews (2024)
Spürbar Nutzen
← SchlechterKein EffektBesser →
There is probably little to no difference in maternal death (2 versus 4 events, RR 0.57, 95% CI 0.12 to 2.69; 3 trials, 14,060 women; moderate-certainty evidence).
Infant outcomes: Women taking iron supplements are probably less likely to have infants with low birthweight (5.2% versus 6.1%; RR 0.84, 95% CI 0.72 to 0.99; 12 trials, 18,290 infants; moderate-certainty evidence), compared to placebo or no iron supplementation.
However, the evidence is very uncertain for infant birthweight (MD 24.9 g, 95% CI -125.81 to 175.60; 16 trials, 18,554 infants; very low-certainty evidence).
4Iron deficiency at termMeta-Analysen=2,822 · very large study2023
Einfach gesagt: Daily iron supplementation in iron replete non-anemic pregnant women probably reduces the risk of maternal iron deficiency anemia at term and low birthweight.
Hansen R et al. · Acta obstetricia et gynecologica Scandinavica (2023)
Groß Nutzen
← SchlechterKein EffektBesser →
In addition, it may reduce iron deficiency at term (RR: 0.74, 95% CI: 0.60-0.92; 4 RCTs, 1663 women; I2 = 58%; low-certainty evidence) and the incidence of small for gestational age babies (RR: 0.39, 95% CI: 0.17-0.86; 1 RCT, 213 infants; I2 not estimable; low-certainty evidence).
Daily iron supplementation in iron replete non-anemic pregnant women probably reduces the risk of maternal iron deficiency anemia at term and low birthweight.
5Anemia prevalenceMeta-Analysen=722 · large study2024
Einfach gesagt: It was found that dietary factors were one of the major causes of anemia, and iron-containing supplements and nutrition counseling could be effective interventions to reduce the prevalence of anemia, ID, and IDA among Chinese pregnant women.
Zhou Y et al. · Nutrients (2024)
Kein klarer Effekt
← SchlechterKein EffektBesser →
The results showed that the prevalence of anemia, ID, and IDA among pregnant women in China were 30.7% (95% CI: 26.6%, 34.7%), 45.6% (95% CI: 37.0%, 54.2%), and 17.3% (95% CI: 13.9%, 20.7%), respectively.
Generally, lower prevalence was observed in the economically more advanced eastern region of the country, while the prevalence of ID was higher in the eastern region than that in the western region.
The prevalence of anemia and IDA in rural areas was higher than that in urban areas, but ID prevalence was higher in urban areas.
6Iron-related parametersMeta-Analysen=529 · large study2024
Einfach gesagt: ALA supplementation had no statistically significant effect on iron-related parameters.
Sharifi-Zahabi E et al. · International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition (2024)
In subgroup analysis, ALA significantly increased hemoglobin in patients with hematological disorders (WMD = 1.23 g/dL; 95% CI: 1.00, 1.45 g/dL; I2 = 96.6%, p < 0.001) and in studies with durations longer than 8 weeks (WMD = 1.03 g/dL; 95% CI: 0.82, 1.25 g/dL; I2 = 96.5%, p = 0.02).
ALA supplementation had no statistically significant effect on iron-related parameters.
7Gastrointestinal side-effectsMeta-Analysen=3,168 · very large study2015
Einfach gesagt: Our meta-analysis confirms that ferrous sulfate is associated with a significant increase in gastrointestinal-specific side-effects but does not find a relationship with dose.
Tolkien Z et al. · PloS one (2015)
Sehr groß Schaden
← SchlechterKein EffektBesser →
Likely real
Ferrous sulfate supplementation significantly increased risk of GI side-effects versus placebo with an odds ratio (OR) of 2.32 [95% CI 1.74-3.08, p<0.0001, I2 = 53.6%] and versus i.v. iron with an OR of 3.05 [95% CI 2.07-4.48, p<0.0001, I2 = 41.6%].
Subgroup analysis in IBD patients showed a similar effect versus i.v. iron (OR = 3.14, 95% CI 1.34-7.36, p = 0.008, I2 = 0%).
Likewise, subgroup analysis of pooled data from 7 RCTs in pregnant women (n = 1028) showed a statistically significant increased risk of GI side-effects for ferrous sulfate although there was marked heterogeneity in the data (OR = 3.33, 95% CI 1.19-9.28, p = 0.02, I2 = 66.1%).
Einfach gesagt: In addition, they further contribute to the ongoing discourse of choosing antenatal MMN over IFA as the standard of care in LMICs.
Oh C et al. · Nutrients (2020)
IFA supplementation showed notable improvement in maternal anemia and the reduction in low birthweight, whereas LNS supplementation had no apparent effect on outcomes; further research that compares LNS and MMN supplementation could help understand differences with these commodities.
For single micronutrient supplementation, improvements were noted in only a few outcomes, mainly pre-eclampsia/eclampsia (calcium), maternal anemia (iron), preterm births (vitamin D), and maternal serum zinc concentration (zinc).
These findings highlight that micronutrient-specific supplementation should be tailored to specific groups or needs for maximum benefit.
9Hemoglobin levelsMeta-Analysen=120 · medium study2024
Einfach gesagt: There is moderate-quality evidence suggesting that probiotics, prebiotics, and synbiotics may improve anemia management, particularly by enhancing Hb levels.
Hu Q et al. · BMC gastroenterology (2024)
Spürbar Nutzen
← SchlechterKein EffektBesser →
Likely real
The analysis revealed that probiotics, prebiotics, or synbiotics significantly improved Hb levels in patients with anemia (WMD = 10.760, 95% CI: 4.593 to 16.747, p = 0.001), though heterogeneity was high (I² = 96.5%).
Two RCTs (n = 120 participants) reported significant increases in serum iron levels in the probiotic group (WMD = 3.835, 95% CI: 3.271 to 4.400), with moderate heterogeneity (I² = 38.7%).
Two RCTs (n = 192 participants) reported no significant differences were observed between the groups in serum ferritin levels (WMD = 8.048, p = 0.115), and heterogeneity remained high (I² = 62.6%).
10Blood iron parametersMeta-Analysen=449 · medium study2024
Einfach gesagt: The doses of OIS, that induced a beneficial effect on hematological parameters differed from 16 to 100 mg of elementary iron daily, over the period between 6 and 8 weeks.
Šmid AN, Golja P, Hadžić V, Abazović E, Drole K, Paravlić AH · Sports Medicine (2024)
11Haemoglobin concentrationMeta-Analysen=8,506 · very large study2016
Einfach gesagt: Daily iron supplementation effectively reduces the prevalence of anaemia and iron deficiency, raises haemoglobin and iron stores, improves exercise performance and reduces symptomatic fatigue.
Low MS et al. · The Cochrane database of systematic reviews (2016)
Spürbar Nutzen
← SchlechterKein EffektBesser →
Women receiving iron had a higher haemoglobin concentration at the end of intervention compared to women receiving control (mean difference (MD) 5.30, 95% CI 4.14 to 6.45, 51 studies, 6861 women, high quality evidence).
Women receiving iron had a reduced risk of iron deficiency compared to women receiving control (RR 0.62, 95% CI 0.50 to 0.76, 7 studies, 1088 women, moderate quality evidence).
Seven trials recruiting 901 women reported on 'any side effect' and did not identify an overall increased prevalence of side effects from iron supplements (RR 2.14, 95% CI 0.94 to 4.86, low quality evidence).