Zinc is known as a micro mineral or trace mineral as it is required by the body in smaller quantities than macro minerals. But this does not mean it is any less important. In fact zinc is so important it is found in every tissue in the body, with the majority found in muscles and bones. It is a constituent of at least 25 enzymes that are involved in digestion and metabolism.
There are many essential functions that zinc plays a role in in the body. One of the most widely known is the role it plays is in immune system function. Of all the minerals zinc has the largest effect of the immune system and on T-cells. Increased levels of zinc have been shown effective in fighting pneumonia, diarrhoea, infections and can reduce the duration and severity of a cold.
Zinc is very important for fertility in both men and women. It protects the prostate gland from infection and enlargement and maintains sperm count and normal testosterone levels in men, and is useful for premenstrual symptoms in women. It is also vital for foetal development, as it is involved in growth and cell division.
As most of the body's zinc is found in muscles and bones it is especially important for muscle cell building and keeping bones strong and healthy. Zinc is involved in the formation of keratin, which forms hair, skin and nails so adequate levels of zinc will keep these tissues healthy. It also aids wound healing and tissue repair.
Zinc is needed for the function of most hormones and neurotransmitters. It plays at least three roles in insulin health so adequate levels of zinc can help protect against insulin resistance. Zinc helps regulate dopamine production which has an effect on mood and emotions. Some studies have also shown that the use of zinc supplementation in children diagnosed with ADHD improved social behaviour and hyperactivity.
Zinc also helps to maintain cardiovascular health as it is a component of endothelial cells that form the lining of blood vessels. Low zinc levels can cause a deficiency of endothelial cells and can lead up to a build up of cholesterol and inflammation.
Zinc acts as an anti-oxidant so is important for protecting against free-radicals and detoxifying. It helps in the elimination of heavy metals such as mercury, cadmium, lead and arsenic, as well as assisting the body to metabolise and eliminate alcohol from the body.
Common signs of zinc deficiency are white spots on nails, brittle finger nails, dull hair, poor appetite, slow wound healing, frequent infections, mood swings, dermatitis, acne, rough and dry skin, and reduced taste and smell. Other more severe signs are delayed sexual maturity, sterility, and stunted and impaired growth in infants, children and adolescents.
ZInc is best absorbed from animal sources. Food sources of zinc are: oysters, meat (especially red), liver, shellfish, poultry, and eggs. Zinc is present in some plants but is less bioavailable than meat sources. It can be found it whole cereals, nuts, green vegetables, and seeds. Dietary intake does not always meet daily requirements and often requires supplementation, especially when deficiency signs are present.