It is found in traces in all body tissues the content being 1.2 grams of it in adults. The highest concentration of it occurs in the liver, pancreas, kidneys and brain. It is also present in red blood cells and blood serum. Zinc is poorly absorbed from the intestine and most of it is excreted in the faeces. A small amount of zinc is also excreted through urine. A high calcium and phytate intake interferes with the absorption of zinc.
Zinc is necessary for the action of various important enzymes like carbonic dehydrogenase, carboxypeptidase and alcohol hydrogenise. It is required for protein synthesis and also for DNA and RNA synthesis in body cells. Zinc accelerates the process of healing of wounds. It combines with the hormone insulin but it is not required for the activity of insulin.
Zinc is widely distributed in both animal and vegetable foods. A normal non-vegetarian diet furnishing sufficient protein will also have enough zinc. Vegetarian diets are low in their zinc content.
The deficiency of zinc among human being is rare. There are reports that cirrhosis of liver, pernicious anaemia, and myocardial infarction occur due to low zinc level in the blood. Certain cases of growth failure (dwarfism) and hypogonadism are associated with zinc deficiency.