IDEAS home Printed from https://ideas.repec.org/p/cgd/wpaper/746.html

Iron and Calcium Supplementation for Reducing Blood Lead Levels: A Systematic Review and Meta-Analysis

Author

Listed:
  • Lee Crawfurd

    (Center for Global Development)

  • Theo Mitchell

    (Center for Global Development)

Abstract

Approximately half of children in low- and middle-income countries have elevated blood lead levels. The WHO recommends calcium and iron supplementation for lead-exposed individuals with nutritional deficiencies, but acknowledges this is based on “very low-certainty evidence.†We conducted a systematic review and meta-analysis of 11 randomized controlled trials (n=3,666 enrolled). Across all seven calcium studies, the pooled effect on blood lead was −1.33 μg/dL (95% CI: −2.87 to +0.21 ; p=.078 ), attenuating to −0.36 μg/dL when restricted to 4 low-risk-of-bias studies. Iron supplementation reduced blood lead by −0.31 μg/dL (95% CI: −0.61 to −0.02 ; p=.045 ). The three studies from settings with widespread calcium deficiency—which are also the three high-risk-of-bias studies—showed substantially larger effects. We rate certainty of evidence as very low for calcium and moderate for iron. These interventions offer modest potential benefits at low cost but cannot substitute for primary prevention.

Suggested Citation

  • Lee Crawfurd & Theo Mitchell, 2026. "Iron and Calcium Supplementation for Reducing Blood Lead Levels: A Systematic Review and Meta-Analysis," Working Papers 746, Center for Global Development.
    • Handle: RePEc:cgd:wpaper:746
    as

    Download full text from publisher

    File URL: https://www.cgdev.org/publication/iron-and-calcium-supplementation-reducing-blood-lead-levels-systematic-review-and-meta?utm_source=repec&utm_medium=referral&utm_campaign=repec
    Download Restriction: no
    ---><---

    More about this item

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:cgd:wpaper:746. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    We have no bibliographic references for this item. You can help adding them by using this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Publications Manager (email available below). General contact details of provider: https://edirc.repec.org/data/cgdevus.html .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.