In practice, problematic claims occur most frequently in dietary supplements. Pursuant to Decree No 225/2008 Coll., the labelling of dietary supplements must not attribute qualities involving the prevention, treatment or cure of human diseases to these foodstuffs nor refer to them. If the manufacturer or importer wishes to manufacture or market foodstuffs whose labelling or advertising for contains a health claim, he/she shall be obliged to proceed in compliance with Section 3d, paragraph 3 of Act No 110/1997 Coll., as amended, i.e. send to the Ministry of Health of the Czech Republic the Czech text of this claim and, upon request, present source materials for the Regulation of the European Communities governing nutrition and health claims on the labelling of foodstuffs (Regulation no. 1924/2006 of the European Parliament and of the Council (EC)).