Trial reportThe American journal of clinical nutrition2011
Long-term effect of low-dose folic acid intake: potential effect of mandatory fortification on the prevention of neural tube defects.
Trial report in The American journal of clinical nutrition, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers.
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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
14 citing papers in PubMed.
- Weekly iron-folic acid supplements containing 2.8 mg folic acid are associated with a lower risk of neural tube defects than the current practice of 0.4 mg: a randomised controlled trial in Malaysia.BMJ global health · 2020Trial
- Defining the plasma folate concentration associated with the red blood cell folate concentration threshold for optimal neural tube defects prevention: a population-based, randomized trial of folic acid supplementation.The American journal of clinical nutrition · 2019Trial
- Response of Red Blood Cell Folate to Supplementation in Nonpregnant Women is Predictable: A Proposal for Personalized Supplementation.Molecular nutrition & food research · 2018Trial
- 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
- Folate catabolites in spot urine as non-invasive biomarkers of folate status during habitual intake and folic acid supplementation.PloS one · 2013Trial
- Persons with epilepsy have an elevated radiosensitivity, which may be mitigated by folic acid.Journal of neurology · 2026Article
- NUQUEST-NUtrition QUality Evaluation Strengthening Tools: development of tools for the evaluation of risk of bias in nutrition studies.The American journal of clinical nutrition · 2022Article
- Freedom-to-operate analysis of a transgenic multivitamin corn variety.Plant biotechnology journal · 2016Article
- Changes in the Incidence of Congenital Anomalies in Henan Province, China, from 1997 to 2011.PloS one · 2015Article
- Effect of increasing voluntary folic acid food fortification on dietary folate intakes and adequacy of reproductive-age women in New Zealand.Public health nutrition · 2014Article
- Revised D-A-CH intake recommendations for folate: how much is needed?European journal of clinical nutrition · 2014Article
- Nutrient intake values for folate during pregnancy and lactation vary widely around the world.Nutrients · 2013Review
- Periconceptional bread intakes indicate New Zealand's proposed mandatory folic acid fortification program may be outdated: results from a postpartum survey.BMC pregnancy and childbirth · 2012Article
- Improvement of the Vietnamese diet for women of reproductive age by micronutrient fortification of staples foods and condiments.PloS one · 2012Article
Corrections and comments
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Authors and funding
6 authors.
Funding
Abstract
backgroundUnderstanding the full effect of chronic low-dose folic acid is important in interpreting the effect of the mandatory folic acid fortification program in North America.
objectiveWe aimed to describe the rate of attainment and steady state (plateau) of red blood cell (RBC) folate in response to long-term intake of 140 μg (designed to mimic fortification) and 400 μg (recommended dose for the primary prevention of neural tube defects) folic acid/d in reproductive-aged women living in a country with minimal fortification.
designOn the basis of pharmacokinetics principles, it was recently proposed that a steady state should be reached after 40 wk. Thus, 144 women aged 18-40 y were randomly assigned to receive a daily folic acid supplement of 140 (n = 49) or 400 (n = 48) μg or placebo (n = 47) for 40 wk. RBC folate was measured at baseline and at 6, 12, 29, and 40 wk.
resultsAfter 40 wk, RBC folate did not reach a plateau in either treatment group. Kinetic modeling of the data indicated that RBC folate would approximately double from 779 to 1356 nmol/L in response to 140 μg folic acid/d with only ≈50% of model-estimated steady state conditions achieved at 40 wk. An average RBC folate concentration of 1068 nmol/L after 12 wk of supplementation with 400 μg folic acid/d was readily achieved at 36 wk after continuous intake of 140 μg/d.
conclusionOur model shows the considerable length of time required to attain the full effect of low-dose folic acid, which suggests that 140 μg folic acid/d could be as effective as 400 μg folic acid/d taken during the periconceptional period if given sufficient time. This trial is registered at www.anzctr.org.au as ACTRN12609000215224.
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