Zinc is an important trace element that the body is unable to produce itself and must absorb from food. A restrictive diet or chronic bowel disorders can cause a zinc deficiency. Otherwise, a balanced diet normally prevents a zinc deficiency.
At a glance
- Zinc is an essential mineral that humans need to absorb into their bodies from food. Zinc is therefore referred to as an essential trace element.
- A balanced diet normally contains enough zinc to meet the body’s requirements.
- Potential causes of a zinc deficiency are a restrictive diet, chronic bowel disorders or taking certain medications.
- Possible symptoms include changes in the skin, increased vulnerability to infections, diarrhea, hair loss and growth delay in children.
- If a zinc deficiency is detected, the person can start taking a zinc supplement following consultation with their doctor.
Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.
What is a zinc deficiency?
Zinc plays an important role in cell division, growth and wound healing. Zinc is also involved in the body’s immune system and in the metabolism of fat and sugar.
People are advised to include zinc in their diet. Examples of foods rich in zinc include red meat, seafood, dairy and wholegrain products, nuts such as cashews and pulses (legumes) like lentils.
In the small intestine, zinc is absorbed from food and passes into the blood and tissues. A deficiency may occur if:
- the person’s diet contains too little zinc
- the absorption of zinc in the intestine is disrupted, for example, because of a chronic bowel disorder
- the person loses a lot of fluids, for example, due to diarrhea
A severe zinc deficiency is a rare occurrence in Germany or Europe.
What are the symptoms of a zinc deficiency?
A zinc deficiency may cause various symptoms.
Signs of a mild deficiency include:
- impaired immunity
- impaired sense of taste and smell
- night blindness
- dry skin and mild skin inflammation
- nail changes
A severe zinc deficiency typically causes skin inflammation with redness, flaky skin and blisters around the mouth and anus, as well as at the elbows, knees, knuckles and ankles. The person suffers more frequent infections because the immune system is significantly impaired.
Other symptoms of a severe deficiency are listed below:
- hair loss
- growth delay in children
- poor wound healing
- vulnerability to infections
- light sensitivity
- loss of appetite
Important: Congenital acrodermatitis enteropathica is an inherited skin condition in which babies are deficient in zinc while they are still breastfeeding. The symptoms of a severe deficiency often become evident between 4 and 6 weeks after breastfeeding has stopped.
What causes a zinc deficiency?
A zinc deficiency may be caused by a lack of zinc in the diet, for example, if following a restrictive diet or eating only plant-based foods.
Phytate can also block the absorption of zinc in the small intestine. Phytate is contained in pulses/legumes, nuts and seeds.
Other causes of a zinc deficiency include chronic inflammatory bowel diseases, such as ulcerative colitis or Crohn’s disease. These can prevent sufficient quantities of zinc entering the bloodstream from the small intestine.
A zinc deficiency may also occur if the body loses excessive amounts of zinc, for example, with diarrhea. Heavy alcohol consumption also causes increased excretion of zinc in urine.
Some types of medication also affects the absorption and excretion of zinc, making a zinc deficiency more likely to develop. These include certain antibiotics to treat bacterial infections and diuretic medication to promote urine production.
With a rare genetic disorder known as congenital acrodermatitis enteropathica, the intestine is unable to absorb zinc.
How can a zinc deficiency be prevented?
Zinc is important for health and normal development during pregnancy, early infancy and childhood. However, there is no need for a zinc supplement to be taken on a precautionary basis. Sufficient quantities of zinc can normally be absorbed from breast milk, baby food and food eaten as part of a normal balanced diet.
People who follow a vegan diet can meet their bodies’ requirement for zinc by ensuring that they eat plenty of zinc-rich foods, such as wholegrain products, pulses/legumes, nuts, soya and wheat and rye germ. Vegetarians can also consume animal products such as eggs, cheese and other dairy products.
Important: Wholegrain products and pulses/legumes also contain phytate – a plant substance that inhibits the absorption of zinc in the intestine. However, processes such as germination, fermentation and soaking help break down phytate and improve zinc absorption.
How is a zinc deficiency diagnosed?
If a patient has symptoms that point to a zinc deficiency or a disease that is frequently associated with a zinc deficiency, the doctor can measure the level of zinc in the patient’s blood.
However, zinc levels can be difficult to evaluate. For one thing, the value may be within the normal range despite the person having a slight zinc deficiency. For another, the level of zinc in the blood often drops due to an acute or chronic infection, even though no zinc deficiency is present.
How is a zinc deficiency treated?
If a zinc deficiency is diagnosed, a zinc supplement can be prescribed by a doctor. A supplement can also be prescribed if a zinc deficiency is suspected.
The supplement is taken daily for several weeks, depending on the cause and severity of the deficiency. Symptoms often resolve within 1 to 2 weeks of starting on a supplement.
Zinc tablets are also an effective treatment for the congenital skin condition acrodermatitis enteropathica, which is associated with a zinc deficiency. People with this disease have to take a supplement for the whole of their lives to counteract the impaired zinc absorption in their intestines.
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In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen – IQWiG). As at: