Trial reportBMC gastroenterology2014
A rapid, simple questionnaire to assess gastrointestinal symptoms after oral ferrous sulphate supplementation.
Trial report in BMC gastroenterology, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 3 registered trials, which are not on this map. Cited by 26 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Validation of a Simple Questionnaire to Assess Gastrointestinal Symptoms After Oral Ferrous Sulphate Supplementation.
A Randomised, Double-blinded, Parallel Group Study to Demonstrate the Adherence and Efficacy of Different Doses of Iron Supplement in Subjects With or At-risk of Iron Deficiency With a History of Intolerance to Oral Iron
Investigation of Efficacy and Gastrointestinal Tolerability of Liposomally Bound Iron Compared to Ferrous Sulphate in Women With Abnormal Uterine Bleeding
Who cites it
26 citing papers in PubMed, 2 syntheses or guidelines pooled it, 58 citations in OpenAlex.
- Daily iron supplementation for improving anaemia, iron status and health in menstruating women.The Cochrane database of systematic reviews · 2016Pooled it
- Ferrous sulfate supplementation causes significant gastrointestinal side-effects in adults: a systematic review and meta-analysis.PloS one · 2015Pooled it
- Acute TRPTI™ (oleoylethanolamide) supplementation enhances incretin hormone responses: a fixed-sequence crossover study.Frontiers in endocrinology · 2026Trial
- The Effects of an Acute Dose of Cannabidiol on Health and Two-Mile Time Trial Performance-A Pilot Study.Nutrients · 2025Trial
- A Multicenter Single-Arm Study of Switching to Ferric Citrate Hydrate for Iron Deficiency Anemia in Patients Intolerant to Oral Iron: RIO-SWITCH.Advances in therapy · 2025Trial
- Trial
- Management of iron deficiency in women of childbearing age with oral iron intolerance: a prospective, randomised, controlled trial of three doses of an iron-whey-protein formulation : Prospective RandomisEd study of women of Childbearing age with gastroInteStinal Intolerance to Oral iroN (PRECISION).International journal of clinical pharmacy · 2024Trial
- Trial
- Tolerability of Oral Supplementation with Microencapsulated Ferric Saccharate Compared to Ferrous Sulphate in Healthy Premenopausal Woman: A Crossover, Randomized, Double-Blind Clinical Trial.International journal of molecular sciences · 2022Trial
- Trial
- Single versus Split Dose of Iron Optimizes Hemoglobin Mass Gains at 2106 m Altitude.Medicine and science in sports and exercise · 2019Trial
- Nicotinamide and Pyruvate in Open-Angle Glaucoma: A Randomized Controlled Trial on Neuroprotection-Design and Methodology.Ophthalmology. GlaucomaTrial
- A Food-Derived Dietary Supplement Containing a Low Dose of Iron Improved Markers of Iron Status Among Nonanemic Iron-Deficient Women.Journal of the American College of NutritionTrial
- The clinical impact of oral iron treatment for anaemia in pregnancy in accordance with current guidance: a prospective cohort study in a maternity unit in the Midlands of England.BMC pregnancy and childbirth · 2025Article
- Diet, Physical Activity and Depression: Does Gastrointestinal Health Help Explain the Relationship Between Lifestyle Factors and Depression?Nutrition bulletin · 2025Article
- Iron mother- protocol for a randomised controlled trial of daily versus alternate day ferrous fumarate for the treatment of iron deficiency anaemia in pregnancy.Contemporary clinical trials communications · 2025Article
- Optimization of Exocrine Pancreatic Insufficiency in Pancreatic Adenocarcinoma Patients.Nutrients · 2024Article
- Scientific opinion on the tolerable upper intake level for iron.EFSA journal. European Food Safety Authority · 2024Article
- Sensory evaluations of a novel iron and zinc-enriched powder for the potential treatment and prevention of iron deficiency in women of reproductive age.Maternal & child nutrition · 2024Article
- Alternate day versus consecutive day oral iron supplementation in iron-depleted women: a randomized double-blind placebo-controlled study.EClinicalMedicine · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors at 2 institutions in 1 country.
Funding
Abstract
backgroundOral iron supplementation is often associated with rapid onset of gastrointestinal side-effects. The aim of this study was to develop and trial a short, simple questionnaire to capture these early side-effects and to determine which symptoms are more discriminating.
methodsThe study was a double-blind placebo-controlled randomized parallel trial with one week treatment followed by one week wash-out. Subjects were randomized into two treatment groups (n = 10/group) to receive either ferrous sulphate (200 mg capsules containing 65 mg of iron) or placebo, both to be taken at mealtimes twice daily during the treatment period. Subjects completed the questionnaires daily for 14 days. The questionnaire included gastrointestinal symptoms commonly reported to be associated with the oral intake of ferrous iron salts (i.e. nausea, vomiting, heartburn, abdominal pain, diarrhoea, and constipation).
resultsSeventy five per cent of participants reporting the presence of one or more symptoms in the first week of the study were in the ferrous sulphate group. In the second week of the study (i.e. wash-out), 67% of the participants reporting one or more symptom(s) were in the ferrous sulphate group. In the first week of the study (treatment) the number of symptoms reported by participants in the ferrous sulphate group (mean ± SEM = 6.7 ± 1.7) was significantly higher than that for participants in the placebo group (1.2 ± 0.5) (p = 0.01). In the second week of the study (wash-out) the number of symptoms reported by participants in the ferrous sulphate group (4.6 ± 2.0) appeared higher than for participants in the placebo group (1.0 ± 0.7) although this did not reach significance (p = 0.12). Events for which the gastrointestinal symptom questionnaire was most discriminatory between ferrous sulphate and placebo groups were: heartburn, abdominal pain and the presence of black stools (all p ≤ 0.03).
conclusionsA tool for the detection of commonly-occurring side effects should not require large study numbers to be effective. With just 10 subjects per group (iron or placebo), this simple questionnaire measures gastrointestinal side-effects associated with oral iron (ferrous sulphate) supplementation, and would be appropriate for use in intervention studies or clinical trials.
trial registrationClinicalTrials.gov Identifier: NCT02146053 (21/05/2014).
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Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.