he efficacy of a chelating agent in
binding a given metal in a biological system
depends on the binding constants of the
chelator for the particular metals in the system,
the concentration of the metals, and the
presence and concentrations of other ligands
competing for the metals in question. In this
study, the comparison is made of the in vitro
binding constants of the chelator,
ethylenediaminotetraacetic acid (EDTA), with
the quantitative urinary excretion of the metal
measured before and after EDTA infusion in 16
patients. There were significant increases in
lead, zinc, cadmium, and calcium, and these
increases roughly corresponded to the
expected relative increases predicted by the
EDTA-metal binding constants as measured in
vitro. There were no significant increases in
urinary cobalt, chromium, or copper as a result
of EDTA infusion. The actual increase in cobalt
could be entirely attributed to the cobalt
content of the cyanocobalamin that was added
to the infusion. Although copper did increase in
the post-EDTA specimens, the increase was
not statistically significant. In the case of
magnesium, there was a net retention of
approximately 85% following chelation. These
data demonstrate that EDTA chelation therapy
results in significantly increased urinary losses
of lead, zinc, cadmium and calcium following
EDTA chelation therapy. There were no
significant changes in cobalt, chromium, or
copper and a retention of magnesium. These
effects are likely to have significant effects on
nutrient concentrations and interactions and
partially explain the clinical improvements seen
in patients undergoing EDTA chelation
therapy.
Waters RS, Bryden NA, Patterson KY, Veillon C,
Anderson RA, Biol Trace Elem Res 2001;83:207-
219
Copyright © 2003 Anamol Laboratories Ltd.
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