Phytic acid occurs in considerable amounts in the seeds of many plants. The unique structure of this compound endows it with a high affinity for all polyvalent cations and the ability to form chelates. The solubility of these complexes is very low, especially in the presence of calcium. The interactions of phytates with proteins are an additional factor worsening the availability of the ions bound in these structures. That is why phytic acid is a factor reducing the absorption of elements from the digestive tract and its presence in food can lead to deficiencies of micro- and macroelements. This adverse effect can be limited by adding phytases to feed so as to hydrolyse phytates. If the feed contains large amounts of such endogenous enzymes, it is sufficient to soak it before feeding to animals.