ABSTRACT
The nutritional essentiality of zinc is based on its biochemical functions which in turn are related to the chemical properties of the element. Metallothionein has important functions in the localization of zinc in tissues, as a major intracellular zinc binding protein, in the intestinal absorption of zinc, in the binding of copper, and in the detoxification of nonessential and toxic element cadmium. Normal absorption of zinc is essential for the maintenance of zinc status and is an important consideration when formulating zinc diets and designing zinc experiments. Pair-feeding is essential when zinc deficient groups are included in experiments because feeding of zinc deficient diet decreases food intake, and as mentioned earlier pair-feeding of the control diet is required to differentiate the effects of zinc deficiency and lowered food intake. Monitoring of food intake of the low zinc group will help ascertain the need for such feeding.
