Its function is purely mechanical and should not be confused with calcium grits, which have a nutritional function as a source of calcium. Contrary to what happens with calcium grits, flint grit is insoluble and does not dissolve in gizzard by the action of gastric acids. In the absence of a contribution of flint grit, it may happen that birds ingest calcium grits in a substitute way in search of a mechanical action that will not occur completely, collaterally causing a potentially harmful hypercalcemia.
