The invention herein disclosed provides compositions comprising a mixture of elastomers and chitosan suitable to reduce the serum levels of phosphorous compounds by up-taking the salivary phosphorous compounds from saliva in situ, i.e. into the mouth cavity, where the chitosan binds the salivary phosphorous compounds and is not released by the compositions themselves either as such or as a complex with said phosphorous compounds. Accordingly, the compositions of the present invention can be usefully used for preventing or treating disorders of phosphorous mineral metabolism associated with altered phosphate homeostasis and to an increased salivary phosphorous levels.
