Trial reportEnvironmental health perspectives2009
Effect of calcium supplementation on blood lead levels in pregnancy: a randomized placebo-controlled trial.
Trial report in Environmental health perspectives, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 83 papers, 5 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
83 citing papers in PubMed, 5 syntheses or guidelines pooled it, 165 citations in OpenAlex.
- Calcium Supplementation in Pregnancy: A Systematic Review of Clinical Studies.Medicina (Kaunas, Lithuania) · 2025Pooled it
- Relationship between lead exposure and different types of hypertension: systematic review and dose-response meta-analysis.Frontiers in public health · 2025Pooled it
- Dietary interventions to reduce heavy metal exposure in antepartum and postpartum women: a systematic review.Women's health nursing (Seoul, Korea) · 2024Pooled it
- Calcium supplementation (other than for preventing or treating hypertension) for improving pregnancy and infant outcomes.The Cochrane database of systematic reviews · 2024Pooled it
- Calcium supplementation (other than for preventing or treating hypertension) for improving pregnancy and infant outcomes.The Cochrane database of systematic reviews · 2015Pooled it
- Making the invisible visible: Developing and evaluating an intervention to raise awareness and reduce lead exposure among children and their caregivers in rural Bangladesh.Environmental research · 2021Trial
- Vitamin D Treatment during Pregnancy and Maternal and Neonatal Cord Blood Metal Concentrations at Delivery: Results of a Randomized Controlled Trial in Bangladesh.Environmental health perspectives · 2020Trial
- Trial
- Effect of calcium supplementation on bone resorption in pregnancy and the early postpartum: a randomized controlled trial in Mexican women.Nutrition journal · 2014Trial
- Blood lead concentration is not altered by high-dose vitamin D supplementation in children and young adults with HIV.Journal of pediatric gastroenterology and nutrition · 2013Trial
- Article
- Heavy Metal Toxicity in Clinical and Environmental Health: Sources, Mechanisms, Diagnostics, and Evidence-Based Management of Mercury, Lead, Cadmium, and Arsenic.International journal of molecular sciences · 2026Review
- Maternal blood lead levels and proximity to legacy mining contamination in Kabwe, Zambia: socioeconomic disparities and potential implications on fetal health.Environmental science and pollution research international · 2026Article
- The Burdens of Idiopathic Developmental Intellectual Disability Attributable to Lead Exposure from 1990 to 2023 and a Projection to 2050 in the USA: Findings from the Global Burden of Disease Study 2023.Healthcare (Basel, Switzerland) · 2026Article
- Metal exposures and their interactions with the dietary inflammatory index on inflammatory biomarkers in Mexican adolescents.Environmental epidemiology (Philadelphia, Pa.) · 2026Article
- Association Between Blood Lead Levels, Haemoglobin and Anaemia in Pregnant Women: A Register-Based Cohort Study From the Autonomous Republic of Adjara, Georgia.Environmental health insights · 2026Article
- International fluoride symposium: effects of fluoride on human health and its mechanisms of action - a meeting report.BMC proceedings · 2025Article
- Lead Poisoning in the Americas: Sources, Regulations, Health Impacts, and Molecular Mechanisms.Journal of xenobiotics · 2025Review
- Dietary Intake Is Associated with Biomarkers of Lead, Arsenic, and Cadmium in a Cohort of Mexican Adolescents.The Journal of nutrition · 2025Article
- Biomarkers for tracking metabolic changes pre-post nutritional epigenetics diet/intervention to prevent autism and attention deficit/hyperactivity disorders in children.World journal of experimental medicine · 2025Review
23 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
8 authors at 3 institutions in 3 countries.
Funding
Abstract
backgroundPrenatal lead exposure is associated with deficits in fetal growth and neurodevelopment. Calcium supplementation may attenuate fetal exposure by inhibiting mobilization of maternal bone lead and/or intestinal absorption of ingested lead.
objectiveOur goal was to evaluate the effect of 1,200 mg dietary calcium supplementation on maternal blood lead levels during pregnancy.
methodsIn a double-blind, randomized, placebo-controlled trial conducted from 2001 through 2003 in Mexico City, we randomly assigned 670 women in their first trimester of pregnancy to ingest calcium (n = 334) or placebo (n = 336). We followed subjects through pregnancy and evaluated the effect of supplementation on maternal blood lead, using an intent-to-treat analysis by a mixed-effects regression model with random intercept, in 557 participants (83%) who completed follow-up. We then conducted as-treated analyses using similar models stratified by treatment compliance.
resultsAdjusting for baseline lead level, age, trimester of pregnancy, and dietary energy and calcium intake, calcium was associated with an average 11% reduction (0.4 microg/dL) in blood lead level relative to placebo (p = 0.004). This reduction was more evident in the second trimester (-14%, p < 0.001) than in the third (-8%, p = 0.107) and was strongest in women who were most compliant (those who consumed > or = 75% calcium pills; -24%, p < 0.001), had baseline blood lead > 5 microg/dL (-17%, p < 0.01), or reported use of lead-glazed ceramics and high bone lead (-31%, p < 0.01).
conclusionCalcium supplementation was associated with modest reductions in blood lead when administered during pregnancy and may constitute an important secondary prevention effort to reduce circulating maternal lead and, consequently, fetal exposure.
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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.