Interactions of trace elements: clinical significance.
Level 5 - mechanism / opinion, no new human data
Narrative review and mechanism-based reasoning with preliminary animal data
PubMed 3886759 · doi:10.1080/07315724.1985.10720064
What was done
The authors reviewed the interactions of zinc with copper and lead based on clinical observations in sickle cell anemia and Wilson's disease, published literature, and preliminary experiments in rats testing the effect of oral zinc on non-oral lead toxicity.
What was found
The abstract reports no numerical data or effect estimates. Zinc deficiency in sickle cell anemia is associated with mild copper overburden and elevated ceruloplasmin, which reverses with zinc supplementation. Pharmacological doses of zinc administered without food deplete copper via intestinal metallothionein induction, inhibiting both dietary absorption and endogenous copper reabsorption to create a negative copper balance in Wilson's disease. In animal studies, oral zinc protects against oral lead toxicity, but preliminary rat experiments showed oral zinc did not mitigate toxicity when lead entered via non-oral routes.
Why it matters
It highlights how competition between trace elements can be harnessed therapeutically, such as using zinc-induced metallothionein to manage copper overload in Wilson's disease, while underscoring the risk of iatrogenic copper deficiency during high-dose zinc therapy.
Limits
The abstract lacks quantitative statistics, sample sizes, patient demographics, and systematic methodology. Much of the evidence rests on mechanistic reasoning and preliminary rodent experiments.
Cited by
- supports Copper and zinc compete with each other for gastrointestinal absorption.