Iron and Increased Ferritin Level

Research synthesisModerate evidenceModerate effect4 studies · 3 beneficial · 1 neutral · 0 harmful

Across 4 studies, 3 reported beneficial effects on ferritin levels, with effect sizes ranging from small to moderate. The predominant effect size was moderate. Studies included iron-deficient women, pregnant women, and athletes, with doses ranging from 4.2 mg to 55 mg/day. Median study duration was 44 days, though only 2 studies reported duration.

Studied populations: iron-deficient individuals, pregnant women, athletes

Caveats: Doses varied widely across studies, and the evidence from the meta-analysis was of very low certainty. One study found a non-significant trend toward benefit (p=0.056). Most studies were in iron-deficient or at-risk populations, so generalizability to iron-replete individuals is unclear.

Generated May 18, 2026

Doses used in studies

mg/day: 4.2–55 (median 20, IQR 4.3–37.5) — 3 studies

Time to effect

Median: 6.3 weeks · IQR 5.1 weeks–7.4 weeks · Range 4 weeks–8.6 weeks — Reported in 2 of 4 studies

Safety in these studies

Overall tolerabilityReported
No studies reported adverse effects.
from: Fortification of condiments and seasonings with iron for preventing anaemia and improving

4 of 4 papersPopulation:

Effect of iron therapy on fatigue symptoms in non-anaemic iron deficient women of reproductive age- A Randomized Controlled Trial.
- 2026-01-01
- RCT · n = 164
- JPMA. The Journal of the Pakistan Medical Association 76(1)
- - Nayyer Sultana
  - Fariha Aslam Bajwa
  - Mirza Zeeshan Sikandar
  - Muhammad Mahtab Haider
  - Tayyaba Majeed
- PubMed: 41736325
- DOI: 10.47391/jpma.22068
3 Insights on
- Increased Ferritin Level
- High evidence
- Large Human Trial
- Clinical
In Group 1, significant decrease in fatigue score and significant increase in ferritin and haemoglobin levels were noted post-intervention (p=0.05).
Effect
Beneficial
Effect size
Small
Significant
Yes
Fortification of condiments and seasonings with iron for preventing anaemia and improving health.
- 2023-09-01
- Meta-Analysis · n = 4,459
- The Cochrane database of systematic reviews 2023(9)
- - Chowdhury Sb Jalal
  - Luz Maria De-Regil
  - Vanessa Pike
  - Prasanna Mithra
- PubMed: 37665781
- DOI: 10.1002/14651858.cd009604.pub2
4 Insights on
- Increased Ferritin Level
- High evidence
- Clinical
We are uncertain about whether fortification with iron plus other micronutrients improves ferritin concentration (MD 10.63 µg/L, 95% CI 2.40 to 18.85; 1251 participants; 5 studies; very low-certainty evidence).
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Dose
4.4–55 mg/day
The effect of Lactiplantibacillus plantarum 299v together with a low dose of iron on iron status in healthy pregnant women: A randomized clinical trial
- 2021-04-21
- RCT
- Acta Obstetricia et Gynecologica Scandinavica 100(9)
- - U. Axling
  - G. Önning
  - Titti Martinsson Niskanen
  - N. Larsson
  - S. Hansson
  - L. Hulthén
- PubMed: 33880752
- DOI: 10.1111/aogs.14153
17 Insights on
- Increased Ferritin Level
- High evidence
- Pregnant Women
Intake of Lp attenuated the decrease in serum ferritin from baseline to week 28 (p = 0.003) and week 35 (p ˂ 0.001)
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Dose
12 mg twice daily
The Effect of Lactobacillus plantarum 299v on Iron Status and Physical Performance in Female Iron-Deficient Athletes: A Randomized Controlled Trial.
- 2020-04-30
- RCT
- Nutrients 12(5)
- - Ulrika Axling
  - Gunilla Önning
  - Maile A Combs
  - Alemtsehay Bogale
  - Magnus Högström
  - Michael Svensson
- PubMed: 32365981
- DOI: 10.3390/nu12051279
4 Insights on
- Increased Ferritin Level
- High evidence
- Rigorous Journal
- Athletes
Intake of Lp299v with iron for four weeks increased ferritin levels more than iron alone (13.6 vs. 8.2 µg/L), but the difference between the groups was not significant (p = 0.056).
Effect
Neutral
Effect size
Small
Significant
No
Dose
20 mg of iron

Iron and Increased Ferritin Level

Effect of iron therapy on fatigue symptoms in non-anaemic iron deficient women of reproductive age- A Randomized Controlled Trial.

Fortification of condiments and seasonings with iron for preventing anaemia and improving health.

The effect of Lactiplantibacillus plantarum 299v together with a low dose of iron on iron status in healthy pregnant women: A randomized clinical trial

The Effect of Lactobacillus plantarum 299v on Iron Status and Physical Performance in Female Iron-Deficient Athletes: A Randomized Controlled Trial.