Zinc

Studies in people

• Open question

  Allergies and the immune system³

  In people, low zinc may be linked to allergies, and zinc supplements may ease symptoms, but study results differ.

• Open question

  Cold duration and side effects⁴

  In people with colds, zinc may shorten how long they last, but may cause more minor side effects.

• Open question

  Kidney health⁵

  People eating less zinc in their food were more likely to develop kidney problems over time.

Study type not stated

• Concern

  Copper and iron absorption⁶

  Too much zinc can stop the body taking in copper and iron, which may lead to anaemia.

• Concern

  Mineral overdose risks⁷

  Taking in too much zinc can cause anemia and lower copper levels in the body.

• Benefit

  Immune system function⁸

  Zinc helps the immune system work, and not getting enough may cause inflammation, though scientists do not yet know all the details.

• Benefit

  Immune system health⁹

  Zinc helps immune cells work and fight bacteria, parasites and viruses, and may help people who don't get enough.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least two findings in people. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.