Zinc is a trace element - an essesntial micro-nutrient required for he healthy functioning of the body. As it is essential to growth, greater levels are required during childhood, adolescence and pregnancy. Certain factors may lead to decreased zinc levels, such as surgery, illness or stress.

There are sixteen recognized trace elemenrts. They are present in the tiniest amounts and measured in parts per million or parts per billion, but their presence is essential to life. They are present in the tissue of all organisms in relatively constant concentrations. The body contains approximately 2g of zinc, second only to iron.

Functions of Zinc

1. A constituent of bones, where most of the zinc in the body is sited. It is therefore vital to growth and development and higher levels are needed in childhood, adolescence, pregnancy or after fracture of a major bone.
2. Vital factor in metabolism. Essential for the production and efficient working of more than 40 enzymes. Crucial in the synthesis of DNA and RNA.
3. Contributes to a healthy skin - 20% of the zinc in the body is sited in the skin.
4. Plays a vital role in immunity and resistance to infection.
5. Needed for the storage and release of insulin. Diabetics can be short of zinc.
6. Vital in healing, especially afer surgery or burns.

Shellfish are high in zinc, as is liver, oxtail and corned beef. Other good sources are nuts, wholegrains and cheese. Wheatgerm, tofu, halva and figs also contain zinc.

Causes of Deficiency

1. Processing of foodstuffs reduces zinc levels and may cause a deficiency in the diet.
2. Low zinc levels in the soil as a result of intensive farming and chemical applications during growth and harvesting of foodstuffs can diminish zinc levels.
3. Certain diseases and illnesses can reduce the absorption of zinc from the intestine.
4. Some drugs, including oral contraceptives, reduce zinc levels in the body.
5. It is absorbed less efficiently with age.
6. Heavy drinking adversely affects the absorption of zinc from the diet.
7. Zinc may be lost in h igh levels in the urine after infectious hepatitis, with burns, after multiple injuries and fracture of major bones.
8. Stress can lead to a zinc deficiency.

1. Loss of sense of small, taste and a healthy appetite. There may be some relationship with anorexia nevorsa and it would seem most likely that in such cases stress results in a zinc deficiency, so causing loss of interest in eating.
2. Pregnant women with a zinc deficiency may be at geater risk of miscarriage, a stillbirth or an underweight baby. As alcohol intake lowers zinc levels, this is a possible reason wby alcohol can be harmful to the foetus. Low levels in pregnancy can also produce congenital abnormalities and if levels are low around the time of the birth, there may be a retardation of growth and subsequent learning difficulties.
3. A lowered resistance to infection and disease.
4. A rare, but interesting phenomenon is the inherited disease acrodermatitis enteropathica. Symptoms are hair loss, skin lessions and diarrhoea. The disease is evident from infancy and if untreated, will be fatal. However, treatment with zinc gives a dramatic improvement and halts progression of the disease. However, life-long supplementation with zinc may be necessary.
5. Atrophy of the thymus gland.

Uses for Zinc Supplementation

Zinc is required in the correct amounts and in balance with other trace elements for general health and well-being. As has been described, certain facors, both physiological and emotional, can cause lowered zinc levels and at such times zinc supplementation may be beneficial.

More specifically, zinc may be used in conjunction with vitamin A for the treatment of dermatitis and acne.

It can also be used in the treatment of the common cold. This was discovered accidentally when a 3-year-old girl, who happened to have a cold, was given zinc for nutiritional purposes by a doctor. She refused to swallow the tablet, but sucked it, with the magic disappearance of the cold. Subsequent trials at Texas University gave an 86% success rate with 25mg zinc daily on a lozenge.

There is no UK RDA at present for zinc, but it is considered that an adult needs approximately 15mg daily.

Zinc competes for absorption with other minerals and taking an iron supplement can reduce the amount of zinc absorbed from the diet.

Zinc taken orally can be detectd in the blood 15minutes after ingerstion and reaches its peak 4 hours later. Hence the quick action seen in the treatment of the cold!