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

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.

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.

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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