From the Guidelines
Elevated zinc levels in the body, known as hyperzincemia, typically require immediate reduction of zinc intake and addressing any underlying causes to prevent toxicity and potential harm to the body, as symptoms can appear when ingestion exceeds 1e2 g of zinc 1. To manage elevated zinc levels, it is essential to:
- Stop taking any zinc supplements or multivitamins containing zinc
- Reduce consumption of zinc-rich foods like oysters, red meat, and fortified cereals temporarily until levels normalize
- Seek medical attention if symptoms like nausea, vomiting, diarrhea, or metallic taste occur
- Consider chelation therapy with medications like penicillamine or EDTA to bind and remove excess zinc in severe cases, as zinc can induce enterocyte metallothionein, a cysteine-rich protein that is an endogenous chelator of metals, and can generate a negative balance for copper and thereby remove stored copper 1 Some key points to consider:
- Elevated zinc can disrupt copper metabolism and immune function, potentially causing copper deficiency anemia and neurological symptoms
- Most cases of hyperzincemia result from excessive supplementation rather than dietary sources alone, so carefully checking all supplement labels for zinc content during recovery is crucial
- Regular monitoring of zinc levels through blood tests is essential until they return to normal (70-120 mcg/dL)
- Drinking plenty of water can help flush excess zinc through urination, and zinc treatment can be effective in removing stored copper, but its use as a first-line therapy in neurological patients requires careful consideration of the potential risks and benefits 1
From the Research
Elevated Zinc Levels
- Elevated zinc levels can be toxic and lead to harmful effects, including anemia, neutropenia, and zinc-induced copper deficiency 2
- The World Health Organization (WHO) recommends a dietary reference value of 6.7 to 15 mg per day, while the European Food Safety Authority (EFSA) defines the tolerable upper intake level (UL) as 25 mg per day 2
- Zinc intake is not limited to oral consumption, and other routes such as inhalation or topical application may also pose risks of zinc intoxication 2
Treatment of Zinc Toxicity
- Chelation therapy with d-penicillamine has been used to treat zinc toxicosis in dogs, with significant improvements in clinical signs and hemogram 3
- D-penicillamine has been shown to catalyze zinc transfer to secondary chelators, leading to complete and essentially irreversible inhibition of zinc proteases 4
- Zinc therapy has been used to maintain treatment after initial penicillamine chelation in patients with symptomatic hepatic Wilson's disease, with significant improvements in liver function tests and disease severity scores 5
Management of Zinc-Related Disorders
- Penicillamine followed by zinc may be a safe and effective treatment for symptomatic hepatic Wilson's disease patients in resource-constrained settings 5
- Withdrawal of penicillamine from zinc sulphate-penicillamine maintenance therapy in Wilson's disease has been shown to be effective, safe, and economic, with most patients remaining stable or improving marginally 6