Zinc Deficiency, Excess and Supplementation - Symptoms

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

What are the symptoms of zinc deficiency?

Symptoms of zinc deficiency depend on how deficient you are. Symptoms may be mild if the zinc level is just a little low, but can be very severe if there is severe deficiency. Symptoms can include:

  • Not wanting to eat.
  • Losing weight.
  • Loose stools (diarrhoea).
  • Having no energy.
  • Being more prone to infections, such as colds, coughs and chest infections.
  • Losing your hair.
  • Skin rashes.
  • Problems with eyesight, taste or smell.
  • Impotence.

In children and adolescents there also can be:

  • Halting of growth.
  • Delayed puberty.
  • Development of learning difficulty.

What are the symptoms of zinc excess?

A number of different symptoms can occur if you have too much zinc on board. For example:

  • Tummy (abdominal) pains
  • Diarrhoea
  • Feeling sick (nausea)
  • Being sick (vomiting)
  • Headaches
  • Tiredness
  • Dizziness

Too much zinc can also affect the levels in your body of other elements, such as iron, copper, magnesium or calcium. There can then be a knock-on effect of lack of these elements - for example, anaemia from a lack of iron.

Excess zinc can also affect the function of your heart and may possibly put you at risk of angina and heart attacks.

A condition called metal fume fever can occur if zinc-containing fumes have been breathed in - for example, during welding or galvanising processes. This causes symptoms such as:

  • A sore throat.
  • Coughing.
  • Difficulty breathing.
  • Chest pains.
  • High temperature (fever).
  • Shakes.
  • Muscle and joint pains.
  • Diarrhoea and vomiting.

Are there any side-effects of zinc supplements?

There are various forms of zinc supplements, containing different doses and forms of zinc. These vary, but some zinc supplements can have side-effects for some people. Many people have no side-effects. Read the information leaflet which comes with the packet. Possible side-effects can include:

  • An unpleasant taste.
  • Headaches.
  • Tummy ache.
  • Feeling sick, or being sick.
  • Diarrhoea.
  • Indigestion.
  • Tiredness.

Never take more than the recommended amount, due to the risks of excess zinc, as described above.

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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