What is zinc?

Zinc is a mineral essential for many of the body's normal functions and systems, including:

• the immune system
• wound healing
• blood clotting
• thyroid function
• senses of taste and smell

Zinc also supports normal growth and development during pregnancy, childhood and adolescence.

Read more on zinc and your health.

What is zinc deficiency?

Zinc deficiency is when the body does not have enough of the mineral zinc for the body's essential functions.

What are the symptoms of zinc deficiency?

Zinc deficiency can result in skin changes that look like eczema at first. There may be cracks and a 'glazed' (smooth or glassy) appearance on the skin. These changes may be noticed first around the mouth, nappy area and hands. The rash doesn't get better with moisturisers, steroid creams or lotions.

People with zinc deficiency may also have:

• hair loss
• skin and hair changes
• eye problems
• more infections than usual
• wounds that take a long time to heal
• loss of taste and smell
• diarrhoea

Zinc deficiency can slow a child's growth, and delay them reaching sexual maturity (puberty).

What causes zinc deficiency?

Zinc deficiency is uncommon, but it can occur if people have medical problems that interfere with zinc absorption from their food, or if they don't have enough zinc in their diet.

Zinc deficiency can happen in people who have problems absorbing nutrients from food, for example, older people and those who have some gastrointestinal (gut) diseases. Some medicines can also increase the loss of zinc through urine.

Zinc from animal-based foods is better absorbed than from plant-based foods. This means that vegetarians and vegans, and people on other long-term restricted diets, may be at a higher risk of zinc deficiency.

Zinc is only found in low amounts in breastmilk, so babies who are exclusively breastfed longer than 6 months may also experience zinc deficiency.

Sometimes, newborn babies experience zinc deficiency if they are premature or very sick, or if their mothers had a mild zinc deficiency. Some people are born with zinc deficiency.

How is zinc deficiency diagnosed?

If you think you or child may have zinc deficiency, see your doctor. They may refer you for a blood test, although this is not very reliable for people with mild deficiency.

Often the best way of diagnosing zinc deficiency is to see if the symptoms improve with a zinc supplement. If you or your child have skin problems related to zinc deficiency, they should start to improve within 72 hours of taking a supplement.

How is zinc deficiency treated?

If you have a diagnosed zinc deficiency, your doctor may recommend this is treated by taking a zinc supplement, usually in the form of a pill or capsule. Your doctor will recommend the right dose for you, depending on your symptoms. You can also get added zinc from some multivitamin supplements, or cold remedies that contain zinc.

It's important to follow your doctor's or pharmacist's recommendations, as having too much zinc can lead to side effects including diarrhoea or vomiting. It can also interfere with the absorption of other nutrients you need, such as copper and iron. You should not take more than 40mg of extra zinc a day, unless your doctor tells you to.

Can zinc deficiency be prevented?

The best way to avoid zinc deficiency for most people is to eat foods that are high in zinc especially dairy foods, poultry, meat and seafood. Zinc can also be found in cereals, legumes, nuts and seeds.

Find out how much zinc you need.

Resources and support

• Visit Nutrition Australia for information about healthy eating.
• Eat for Health uses the Australian dietary guidelines to provide advice about the amount and types of food you need.