Effects of Iron and/or Zinc Supplementation in Mexican School Children Exposed to Lead

NCT ID: NCT02346188

Last Updated: 2015-01-26

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

602 participants

Study Classification

INTERVENTIONAL

Study Start Date

2000-01-31

Study Completion Date

2001-12-31

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Lead is negatively linked to nutritional status, behavior and cognition in children. Despite extensive knowledge of its toxicity and efforts to reduce exposure, lead continues to be a problem in developed and developing countries. When lead exposure is unavoidable due to its pervasive nature, effective means of protecting or disrupting that exposure need to be developed. Nutritional interventions are one such option. We conducted a 2x2 factorial, placebo-controlled trial of 6-month iron and zinc supplementation among lead-exposed children in Torreón, Mexico (altitude 1060 m). Nine schools were selected based on proximity to a lead smelter and first-graders were individually randomized to daily treatment with 30 mg iron, 30 mg zinc, both, or placebo. In addition to biochemical indicators, cognitive functions and behavior were evaluated at baseline, after the 6-month supplementation period, and again after another 6 months (without supplementation).

At baseline, 602 children ages 6.2-8.5 years were enrolled.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

We conducted a 2x2 factorial, placebo-controlled trial of 6-month iron and zinc supplementation among lead-exposed children in Torreón, Mexico (altitude 1060 m) to test the hypothesis that supplementation with iron, zinc or both will reduce blood lead concentrations of the children and improve their cognition and behavior. Nine schools were selected based on proximity to a lead smelter and first-graders were individually randomized to daily treatment with 30 mg iron, 30 mg zinc, both, or placebo. In addition to biochemical indicators (blood lead, serum ferritin, CRP, serum zinc, urinary arsenic concentrations), cognitive functions and behavior were measured. Assessments were conducted at three time points: at baseline, after the 6 month treatment, and again after another 6 months without treatment. At baseline, 602 children ages 6.2-8.5 years were enrolled.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Lead Poisoning

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

FACTORIAL

Primary Study Purpose

TREATMENT

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Ferrous fumarate

Tablet formulated as ferrous fumarate, 30 mg. Given once daily for 6 months.

Group Type EXPERIMENTAL

Ferrous fumarate

Intervention Type DIETARY_SUPPLEMENT

Tablet formulated from 30 mg ferrous fumarate.

Zinc oxide

Tablet formulated as zinc oxide, 30 mg. Given once daily by mouth for 6 months.

Group Type EXPERIMENTAL

Zinc oxide

Intervention Type DIETARY_SUPPLEMENT

Tablet formulated from 30 mg zinc oxide

Ferrous fumarate and zinc oxide

Tablet, formulated as ferrous fumarate 30 mg plus zinc oxide 30 mg. Given once daily by mouth for 6 months.

Group Type EXPERIMENTAL

Ferrous fumarate

Intervention Type DIETARY_SUPPLEMENT

Tablet formulated from 30 mg ferrous fumarate.

Zinc oxide

Intervention Type DIETARY_SUPPLEMENT

Tablet formulated from 30 mg zinc oxide

Placebo

Sugar tablet formulated to look like the experimental arms of the study. Given daily by mouth for 6 months.

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type DIETARY_SUPPLEMENT

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Ferrous fumarate

Tablet formulated from 30 mg ferrous fumarate.

Intervention Type DIETARY_SUPPLEMENT

Zinc oxide

Tablet formulated from 30 mg zinc oxide

Intervention Type DIETARY_SUPPLEMENT

Placebo

Intervention Type DIETARY_SUPPLEMENT

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* 1st grade child

Exclusion Criteria

* Blood lead concentration =\>45 ug/dL
* Hemoglobin concentration \< 9 g/dL
Minimum Eligible Age

6 Years

Maximum Eligible Age

8 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

National Institute of Medical Sciences and Nutrition, Salvador Zubiran

OTHER

Sponsor Role collaborator

National Polytechnic Institute, Mexico

OTHER

Sponsor Role collaborator

Johns Hopkins Bloomberg School of Public Health

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Rebecca J Stoltzfus, PhD

Role: PRINCIPAL_INVESTIGATOR

Johns Hopkins Bloomberg School of Public Health

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Johns Hopkins Bloomberg School of Public Health

Baltimore, Maryland, United States

Site Status

Countries

Review the countries where the study has at least one active or historical site.

United States

References

Explore related publications, articles, or registry entries linked to this study.

Kordas K, Lopez P, Rosado JL, Garcia Vargas G, Alatorre Rico J, Ronquillo D, Cebrian ME, Stoltzfus RJ. Blood lead, anemia, and short stature are independently associated with cognitive performance in Mexican school children. J Nutr. 2004 Feb;134(2):363-71. doi: 10.1093/jn/134.2.363.

Reference Type RESULT
PMID: 14747673 (View on PubMed)

Kordas K, Canfield RL, Lopez P, Rosado JL, Vargas GG, Cebrian ME, Rico JA, Ronquillo D, Stoltzfus RJ. Deficits in cognitive function and achievement in Mexican first-graders with low blood lead concentrations. Environ Res. 2006 Mar;100(3):371-86. doi: 10.1016/j.envres.2005.07.007. Epub 2005 Sep 19.

Reference Type RESULT
PMID: 16169549 (View on PubMed)

Kordas K, Stoltzfus RJ, Lopez P, Rico JA, Rosado JL. Iron and zinc supplementation does not improve parent or teacher ratings of behavior in first grade Mexican children exposed to lead. J Pediatr. 2005 Nov;147(5):632-9. doi: 10.1016/j.jpeds.2005.06.037.

Reference Type RESULT
PMID: 16291354 (View on PubMed)

Rico JA, Kordas K, Lopez P, Rosado JL, Vargas GG, Ronquillo D, Stoltzfus RJ. Efficacy of iron and/or zinc supplementation on cognitive performance of lead-exposed Mexican schoolchildren: a randomized, placebo-controlled trial. Pediatrics. 2006 Mar;117(3):e518-27. doi: 10.1542/peds.2005-1172.

Reference Type RESULT
PMID: 16510631 (View on PubMed)

Rosado JL, Lopez P, Kordas K, Garcia-Vargas G, Ronquillo D, Alatorre J, Stoltzfus RJ. Iron and/or zinc supplementation did not reduce blood lead concentrations in children in a randomized, placebo-controlled trial. J Nutr. 2006 Sep;136(9):2378-83. doi: 10.1093/jn/136.9.2378.

Reference Type RESULT
PMID: 16920858 (View on PubMed)

Rosado JL, Ronquillo D, Kordas K, Rojas O, Alatorre J, Lopez P, Garcia-Vargas G, Del Carmen Caamano M, Cebrian ME, Stoltzfus RJ. Arsenic exposure and cognitive performance in Mexican schoolchildren. Environ Health Perspect. 2007 Sep;115(9):1371-5. doi: 10.1289/ehp.9961.

Reference Type RESULT
PMID: 17805430 (View on PubMed)

Kordas K, Casavantes KM, Mendoza C, Lopez P, Ronquillo D, Rosado JL, Vargas GG, Stoltzfus RJ. The association between lead and micronutrient status, and children's sleep, classroom behavior, and activity. Arch Environ Occup Health. 2007 Summer;62(2):105-12. doi: 10.3200/AEOH.62.2.105-112.

Reference Type RESULT
PMID: 18316268 (View on PubMed)

Roy A, Kordas K, Lopez P, Rosado JL, Cebrian ME, Vargas GG, Ronquillo D, Stoltzfus RJ. Association between arsenic exposure and behavior among first-graders from Torreon, Mexico. Environ Res. 2011 Jul;111(5):670-6. doi: 10.1016/j.envres.2011.03.003. Epub 2011 Mar 25.

Reference Type RESULT
PMID: 21439564 (View on PubMed)

Moodie S, Ialongo N, Lopez P, Rosado J, Garcia-Vargas G, Ronquillo D, Kordas K. The conjoint influence of home enriched environment and lead exposure on children's cognition and behaviour in a Mexican lead smelter community. Neurotoxicology. 2013 Jan;34:33-41. doi: 10.1016/j.neuro.2012.10.004. Epub 2012 Oct 27.

Reference Type RESULT
PMID: 23110976 (View on PubMed)

Kordas K, Roy A, Lopez P, Garcia-Vargas G, Cebrian ME, Vera-Aguilar E, Rosado JL. Iron and Zinc Supplementation Does Not Impact Urinary Arsenic Excretion in Mexican School Children. J Pediatr. 2017 Jun;185:205-210.e1. doi: 10.1016/j.jpeds.2017.02.040. Epub 2017 Mar 23.

Reference Type DERIVED
PMID: 28343659 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

H.22.00.07.06B

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.

Guatemala Biofortified Maize Study
NCT06650397 RECRUITING NA
Micronutrients and Child Health Study
NCT00623857 COMPLETED PHASE3