Zinc is an important mineral, which is essential for protein synthesis and helps to regulate the production of cells in the body's immune system. It is mainly found in the muscles. Zinc is also found in high concentrations in red and white blood cells, the retina of the eye, bones, skin, kidneys, liver, and pancreas. In men, the prostate gland and semen (zinc is one of its constituents) store high amounts of zinc.

More than 300 enzymes in the human body require zinc for normal functioning. It is believed that around 3000 out of the 100,000 proteins involved in human life contain zinc. Our body contains about 2-3 g of zinc.

Many organs of the body secrete zinc, including the pancreas, the salivary gland, and the prostate gland. Immune cells also secrete zinc.

Benefits of zinc

• Zinc is vital to many biological functions such as immune resistance, digestion, reproduction, physical growth, diabetes control, appetite, stress level, taste and smell.
• It helps maintain normal taste and sense of smell, aids in wound healing, promotes normal foetal growth and boosts immunity. By boosting the immune system, zinc also helps protect against fungal infections and various infectious disorders, such as conjunctivitis and pneumonia.
• Zinc functions as an antioxidant and is involved in many decisive biochemical reactions, including enzymatic function, carbohydrate metabolism and protein synthesis.
• It plays an important role as a component of many enzymes regulating cell growth, DNA and protein synthesis, energy metabolism, regulation of gene transcription, hormonal levels in the body etc.
• It is required for fighting skin problems such as acne, boils and sore throats.
• It is also used as an astringent and an antiseptic for skin protection.
• Zinc is especially important for the prostate gland in males, and protects it from early damage that could lead to cancer.
• Zinc also promotes normal growth and development during pregnancy, childhood, and adolescence (sexual development).

What foods are rich sources of zinc?

High-protein foods contain high amounts of zinc. Good food sources for vegetarian people include dairy products (milk, curd, yoghurt), beans and lentils, peanuts, peanut butter, seeds, fortified breakfast cereals, and wholegrain cereals. Pumpkin seeds are considered to be one of the most concentrated vegetarian dietary sources of zinc.

Dietary fibre (phytates, found in cereals, legumes) can interfere with the body's ability to absorb zinc. Zinc is best absorbed by the body when taken with a meal that contains protein.

Red meat and poultry also provide good sources of zinc. Zinc absorption is greater from a diet high in animal protein than a diet rich in plant proteins. Thus, fruits and vegetables are not good sources of zinc.

Cooking helps reduce the adverse effects of both phytic acid and dietary fibre on zinc absorption.

Is excess zinc harmful?

Too much zinc can be harmful to the human body. Excessive absorption of zinc into the human body can lead to reduced iron function, and damage the immune system. The major adverse outcome of long-term consumption of excessive zinc is copper deficiency, along with stomachache, nausea, mouth irritation, and a bad taste.