Zinc is absorbed through the gut in a delicate balance with other essential minerals such as copper and iron. Humans easily absorb the zinc we need from what we eat. If zinc is low in the blood, we efficiently take up as much as needed to get us back on par. Supplementation not only interferes with the normal absorption from food intake, it competes with the absorption of copper essential for liver function. While meats and poultry are a primary source of zinc, it is also abundant in eggs, cheese, chickpeas and whole grains.
Phytic acid inhibits zinc absorption.
Therefore, bran and other cereals must be cooked to lessen that effect. The U. S. Department of Agriculture has studied zinc in the vegetarian diet. There was no net body loss of zinc. The USDA concluded that vegetarians compensate by absorbing zinc more efficiently from food and excreting less of it. The symptoms of a slight zinc deficiency are unnoticeable and totally reversible causing no permanent problems.