Lead Chelation Therapy Drains Zinc and Selenium in Occupationally Exposed Workers

Chelation therapy with calcium disodium EDTA (CaNa₂EDTA) is a cornerstone treatment for workers with chronic occupational lead poisoning, but a new real-world analysis from Türkiye suggests the treatment comes with an underappreciated cost: significant and sustained losses of essential trace elements, most notably zinc and selenium. The study, published in BMC Pharmacology and Toxicology, tracked serial blood concentrations of six essential trace elements across repeated chelation cycles in 257 lead-intoxicated patients.

The retrospective study drew on patients treated between November 2021 and November 2025 at a national referral center in Türkiye. In total, 257 patients with occupational chronic lead intoxication—98.1 percent of them male—accounted for 314 hospitalizations and 538 CaNa₂EDTA chelation cycles. The median blood lead concentration at admission was 52 µg/dL, with an interquartile range of 43.5 to 63 µg/dL, indicating substantial chronic exposure in this workforce.

The researchers measured blood levels of zinc, selenium, copper, chromium, manganese, and molybdenum at baseline and after each chelation cycle. To handle the unbalanced, repeated-measure structure of the data, they used linear mixed-effects models with each patient as a random intercept, applying Bonferroni-adjusted pairwise comparisons and sensitivity analyses to guard against spurious findings.

The results were strikingly element-specific. Zinc and selenium concentrations declined markedly after the first chelation cycle, with p-values below 0.001, and remained significantly below baseline throughout all subsequent cycles. In other words, the depletion was not a one-time perturbation but a sustained shift that persisted across the full course of treatment. Copper and molybdenum showed smaller, transient reductions that reached statistical significance only after the first cycle—p < 0.001 for copper and p = 0.003 for molybdenum—before recovering toward baseline in later cycles.

Not every essential element was affected. Chromium and manganese concentrations remained stable throughout treatment, with p-values of 0.425 and 0.252, respectively, indicating that CaNa₂EDTA does not uniformly reduce all measured trace elements. The study was designed to characterize these patterns rather than to establish the mechanisms behind them.

One further finding stood out: a dose-dependent effect was observed for zinc alone, with greater reductions at higher EDTA doses (p = 0.002). This gradient means that patients receiving more intensive chelation experienced larger zinc declines, a pattern that could inform how clinicians weigh monitoring intensity against treatment dosing.

The authors conclude that element-specific changes in trace element concentrations occur during repeated CaNa₂EDTA therapy, with zinc and selenium showing the most pronounced and sustained reductions after the first cycle. On that basis, they support targeted monitoring of zinc and selenium during repeated chelation, with supplementation considered if deficiency is confirmed or clinically indicated. Importantly, the study documents associations between chelation exposure and trace element declines; it did not test whether supplementation improves outcomes, so any supplementation decisions would rest on confirmed deficiency or clinical judgment rather than on demonstrated benefit from this study.

As a retrospective, single-center analysis, the study has inherent limitations. It captures real-world practice at a national referral center, which strengthens relevance for similar occupational medicine settings, but it cannot randomize treatment or control all sources of variation in diet, exposure, and co-administered therapies. The overwhelmingly male cohort also limits generalizability to female workers. Even so, the scale of the dataset—538 chelation cycles with serial measurements across six elements—offers a detailed portrait of how repeated chelation reshapes the body’s trace metal economy, and it gives clinicians a concrete, evidence-based shortlist of which elements to watch when lead-poisoned workers undergo repeated chelation.

Subject of Research: Effects of EDTA chelation therapy on essential trace elements in occupational chronic lead intoxication

Article Title: Impact of EDTA chelation therapy on essential trace elements in patients with occupational chronic lead intoxication: a real-world data analysis

Article References: Balaban, U., Yildiz Balaban, T., Akkale, T., Baskara, C., Sandal, A., & Demirkan, K. (2026). Impact of EDTA chelation therapy on essential trace elements in patients with occupational chronic lead intoxication: a real-world data analysis. BMC Pharmacology and Toxicology. https://doi.org/10.1186/s40360-026-01267-0

Image Credits: AI Generated

DOI: 10.1186/s40360-026-01267-0

Keywords: chelation therapy, CaNa2EDTA, lead poisoning, zinc, selenium, trace elements, occupational medicine, toxicology, real-world study, Türkiye, heavy metals, drug safety