Zinc Deficiency, Excess and Supplementation

Authored by Dr Mary Harding, 30 May 2017

Patient is a certified member of
The Information Standard

Reviewed by:
Dr John Cox, 30 May 2017

Zinc is needed for many of the chemical reactions which are going on inside us all the time at micro-level. Zinc is also needed for:

  • Our immune systems to work well to fight off infection.
  • Healing of wounds.
  • Growing.
  • Building the proteins and molecules which are the basis of all our cells.
  • Taste, smell and good vision.

Zinc is readily available in many foods including:

  • Red meat
  • Chicken and other poultry
  • Seafood, particularly oysters (which are loaded with zinc), crab and lobster
  • Nuts
  • Grains, beans, lentils and split peas
  • Spinach
  • Dairy products - milk, yoghurt, cheese
  • Fortified breakfast cereal.

What happens if we don't have enough, or too much of it?

Not having enough zinc can cause a whole host of physical symptoms, ranging from mild to life-threatening. Occasionally, people become ill from having too much zinc (zinc toxicity)

Further reading and references

  • Evans JR, Lawrenson JG; Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration. Cochrane Database Syst Rev. 2012 Nov 1411:CD000254. doi: 10.1002/14651858.CD000254.pub3.

  • Singh M, Das RR; Zinc for the common cold. Cochrane Database Syst Rev. 2013 Jun 186:CD001364. doi: 10.1002/14651858.CD001364.pub4.

  • Lazzerini M, Wanzira H; Oral zinc for treating diarrhoea in children. Cochrane Database Syst Rev. 2016 Dec 2012:CD005436. doi: 10.1002/14651858.CD005436.pub5.

  • Allan GM, Arroll B; Prevention and treatment of the common cold: making sense of the evidence. CMAJ. 2014 Feb 18186(3):190-9. doi: 10.1503/cmaj.121442. Epub 2014 Jan 27.

  • Saper RB, Rash R; Zinc: an essential micronutrient. Am Fam Physician. 2009 May 179(9):768-72.

  • Zinc. Consumer Fact Sheet; National Institute of Health Office of dietary supplements

  • Acrodermatitis enteropathica; DermNet NZ

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