Effects of Iron and/or Zinc Supplementation in Mexican School Children Exposed to Lead
- Conditions
- Lead Poisoning
- Interventions
- Dietary Supplement: Ferrous fumarateDietary Supplement: Zinc oxideDietary Supplement: Placebo
- Registration Number
- NCT02346188
- Lead Sponsor
- Johns Hopkins Bloomberg School of Public Health
- Brief Summary
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
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.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 602
- 1st grade child
- Blood lead concentration =>45 ug/dL
- Hemoglobin concentration < 9 g/dL
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- FACTORIAL
- Arm && Interventions
Group Intervention Description Ferrous fumarate Ferrous fumarate Tablet formulated as ferrous fumarate, 30 mg. Given once daily for 6 months. Zinc oxide Zinc oxide Tablet formulated as zinc oxide, 30 mg. Given once daily by mouth for 6 months. Ferrous fumarate and zinc oxide Ferrous fumarate Tablet, formulated as ferrous fumarate 30 mg plus zinc oxide 30 mg. Given once daily by mouth for 6 months. Ferrous fumarate and zinc oxide Zinc oxide Tablet, formulated as ferrous fumarate 30 mg plus zinc oxide 30 mg. Given once daily by mouth for 6 months. Placebo Placebo Sugar tablet formulated to look like the experimental arms of the study. Given daily by mouth for 6 months.
- Primary Outcome Measures
Name Time Method Blood lead concentration 6-12 months
- Secondary Outcome Measures
Name Time Method Anthropometric composite 6-12 months Height, weight
Serum ferritin concentration 6-12 months Serum zinc concentration 6-12 months Hemoglobin concentration 6-12 months Peabody Picture Vocabulary Test, Math achievement test, tests of attention and memory 6-12 months Conners Behavior Rating Scales for parents and teachers 6-12 months
Trial Locations
- Locations (1)
Johns Hopkins Bloomberg School of Public Health
🇺🇸Baltimore, Maryland, United States