Zinc (Zn) is an essential mineral in the body for the functioning of many enzymes. It is obtained from a wide range of foods in the diet, and the recommended daily intake is 12 mg a day in adults. The amount present in the body can be measured by a blood test and the normal range is 12 to 20 µmol/L (80-140 µg/100 mL).
Low levels may be found in cirrhosis, diarrhoea, malabsorption syndromes, alcoholism, and after the use of drugs such as steroids and diuretics.
Urinary zinc levels can also be measured. The normal range is 8 to 11 µmol/day and higher levels may indicate catabolic (tissue breakdown) diseases and excess zinc in blood. Low levels may result in liver disease and poor wound healing may result. The urinary level is an indication of the amount of available zinc in the body.
Zinc is included in many mineral and vitamin supplements, as well as cold and flu medications. It may be useful in the treatment of zinc deficiency, the common cold, mouth ulcers and aid wound healing.
Supplements may alter blood test results and sometimes cause nausea, chest pain and anaemia.