ArticleBMJ open2012
Cancer risk with folic acid supplements: a systematic review and meta-analysis.
Article in BMJ open, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 80 papers, 10 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.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
80 citing papers in PubMed, 10 syntheses or guidelines pooled it, 200 citations in OpenAlex.
- Folate and global health umbrella review series, part 2: syntheses on cancers.Journal of global health · 2026Pooled it
- Evaluating agreement between individual nutrition randomised controlled trials and cohort studies - a meta-epidemiological study.BMC medicine · 2025Pooled it
- Nutrigenetic Investigations in Preeclampsia.Nutrients · 2024Pooled it
- Pooled it
- Association Between Folate and Health Outcomes: An Umbrella Review of Meta-Analyses.Frontiers in public health · 2020Pooled it
- Fortification of wheat and maize flour with folic acid for population health outcomes.The Cochrane database of systematic reviews · 2019Pooled it
- Assessing the causal association of glycine with risk of cardio-metabolic diseases.Nature communications · 2019Pooled it
- Folate intake, serum folate levels, and prostate cancer risk: a meta-analysis of prospective studies.BMC public health · 2014Pooled it
- Folate intake and the risk of prostate cancer: a systematic review and meta-analysis.Prostate cancer and prostatic diseases · 2014Pooled it
- Effects of folic acid supplementation on overall and site-specific cancer incidence during the randomised trials: meta-analyses of data on 50,000 individuals.Lancet (London, England) · 2013Pooled it
- Response of serum and red blood cell folate concentrations to folic acid supplementation depends on methylenetetrahydrofolate reductase C677T genotype: results from a crossover trial.Molecular nutrition & food research · 2013Trial
- Effect of folic acid supplementation in pregnancy on preeclampsia: the folic acid clinical trial study.Journal of pregnancy · 2013Trial
- Pro-Carcinogenic Implications of Folic Acid Supplementation During Chemically Induced Cutaneous Squamous Cell Carcinoma in Mice.Journal of biochemical and molecular toxicology · 2026Article
- Folate-Containing Fermented Foods of Plant and Animal Origin: The Value of Traditional Foods to Tackle Folate Deficiency.Food science & nutrition · 2026Review
- Association Between Dietary Folate and Prostate Cancer Aggressiveness Among African Americans and European Americans.Nutrients · 2026Article
- Biological, dietetic and pharmacological properties of vitamin BNPJ science of food · 2025Review
- High-dose folic acid use and cancer risk in women who have given birth: A register-based cohort study.Epilepsia · 2025Article
- Association of serum folate concentrations with cancer mortality among patients with arthritis: a prospective cohort study.BMC public health · 2024Article
- In Vivo and In Vitro Studies Assessing the Safety of Monosodium Glutamate.Foods (Basel, Switzerland) · 2024Article
- Possible hemoglobin enhancing effect of phytol in methotrexate-induced folate deficientPharmaceutical science advances · 2024Article
20 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Objective To explore if there is an increased cancer risk associated with folic acid supplements given orally. Design Systematic review and meta-analysis of controlled studies of folic acid supplementation in humans reporting cancer incidence and/or cancer mortality. Studies on folic acid fortification of foods were not included. Data sources Cochrane Library, Medline, Embase and Centre of Reviews and Dissemination, clinical trial registries and hand-searching of key journals. Results From 4104 potential references, 19 studies contributed data to our meta-analyses, including 12 randomised controlled trials (RCTs). Meta-analysis of the 10 RCTs reporting overall cancer incidence (N=38 233) gave an RR of developing cancer in patients randomised to folic acid supplements of 1.07 (95% CI 1.00 to 1.14) compared to controls. Overall cancer incidence was not reported in the seven observational studies. Meta-analyses of six RCTs reporting prostate cancer incidence showed an RR of prostate cancer of 1.24 (95% CI 1.03 to 1.49) for the men receiving folic acid compared to controls. No significant difference in cancer incidence was shown between groups receiving folic acid and placebo/control group, for any other cancer type. Total cancer mortality was reported in six RCTs, and a meta-analysis of these did not show any significant difference in cancer mortality in folic acid supplemented groups compared to controls (RR 1.09, 95% CI 0.90 to 1.30). None of the observational studies addressed mortality. Conclusions A meta-analysis of 10 RCTs showed a borderline significant increase in frequency of overall cancer in the folic acid group compared to controls. Overall cancer incidence was not reported in the seven observational studies. Prostate cancer was the only cancer type found to be increased after folic acid supplementation (meta-analyses of six RCTs). Prospective studies of cancer development in populations where food is fortified with folic acid could indicate whether fortification similar to supplementation moderately increases prostate cancer risk.
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.