Zinc is a trace mineral that has been shown to be deficient in some New Zealand soils, so it is a particularly important mineral to monitor.
It is not the easiest mineral to be absorbed. Due to our western diet only about 15% to 60% of dietary zinc is actually absorbed.
Phytates and fibre (which occur naturally in whole grains, legumes, nuts and seeds) bind with the zinc slowing its absorption. Some of these foods can be soaked or cooked to lessen their phytate content.
However, when you eat high-phytate foods with most of your meals, mineral deficiencies may develop over time.
If a diet is deficient in zinc the body is very clever and will increase its uptake. As long as a balanced diet (with a wide variety of foods) is being consumed, there should be no major problems. Meat, poultry and seafood are the best sources of zinc, with oysters being particularly high. Milk, fruit and vegetables generally are low in zinc.
However, if someone is living on a high wheat/bran diet or eating excessive amounts of grains they could be losing more zinc than they should. The phytates bind to the mineral and withdraw the zinc from the body via our faeces.
Zinc is vital for strong immune health and to complete some metabolic pathways, zinc must be present. It is essential for growth, physical development and virtually every enzyme reaction in the brain involves zinc.
A zinc deficiency early in life results in impaired growth and sexual development. In studies of zinc deficient rats, the female rats fail to have a cycle and the males show atrophy (wasting away) of the testicles and do not produce sperm.
When our immune system is sluggish wounds are slow to heal – this is just one sign of zinc deficiency. Taste and smell can also be adversely affected. This essential mineral is involved with immunity, insulin, thyroid function, reproduction, digestion and is important for prostate health. Severe zinc deficiency results in impairment of the immune system and increased infections.
Zinc levels will drop from normal levels during times of severe illness or inflammation, so it is a great choice for supplementation over winter months and seasonal changes. It is helpful in preventing and shortening the duration of a respiratory illness and is best taken at the first sign of infection. The immune system involves a large array of signalling proteins and DNA binding proteins which require zinc for activity. High alcohol intake also increases the requirement for zinc, as is required for alcohol dehydrogenase (an enzyme required for alcohol metabolism) consequently high alcohol intake will lower your immunity.
Zinc is relatively non-toxic, however large ongoing doses can interfere with the intake of other minerals and can in fact lower immunity. Like many natural and orthodox medications, if correct dosing is not followed, you can start to create what you are trying to treat, so please consult with your health professional where necessary.