What is zinc and why is it important?
Find out why zinc is important for good health and the problems with over-supplementing.
What is zinc?
The body needs a variety of vitamins and minerals to function properly. One essential mineral is zinc which is a co-factor for many different enzymes and involved in many important processes in the body. Zinc is an ‘essential trace mineral’ as the body does not produce or store excess zinc so it must be consumed regularly as part of our diet. Only very small amounts are required in the body. Zinc is involved in the major metabolic pathways concerned with protein, lipid, carbohydrate and energy metabolism. The mineral is also necessary for a healthy immune system, wound healing, DNA synthesis, taste, smell and is essential for cell division and growth.
What are good dietary sources of zinc?
Zinc is naturally present in some foods, added to others and available as a dietary supplement. A wide variety of foods contain zinc including red meat, dairy products, oysters, whole grains, chickpeas, fortified cereals, beans and nuts. The NHS recommends 9.5mg of zinc a day for men (aged 19 to 64 years) and 7mg a day for women. You should be able to get all the zinc you need from your daily diet.
Because zinc is involved in so many reactions in the body, there is no single distinct symptom of a zinc deficiency. In the UK zinc deficiencies are rare as most people should be able to get all the zinc they need from their daily diet. Symptoms may include:
- Unexplained weight loss
- Wounds that won’t heal
- Diminished smell and taste
- Metallic taste in the mouth
- Cracked/peeling lips
A number of different forms of zinc are available as supplements, including zinc sulfate, zinc gluconate and zinc acetate. Zinc supplements must be used with caution as they can have toxicity and side effects when taken in high doses for a long period of time. Too much zinc increases the risk of a copper deficiency, as zinc interferes with copper absorption. Because copper is essential for making healthy red blood cells, too little copper can cause anaemia. The Department of Health in the UK advises that intake of zinc should not exceed 25 mg per day. High doses of zinc can also cause digestive and renal problems, so do not take high doses of zinc without first speaking with your doctor.