A composition for use in the treatment of a disorder characterized by a high serum phosphate concentration, the composition comprising an amount of pharmaceutical grade ferric citrate effective to reduce serum phosphate concentrations, where the administered amount of pharmaceutical grade ferric citrate it is from 2 grams per day to 30 grams per day and where ferric citrate can be obtained by a method comprising the steps of: a) dissolving an adequate amount of ferric chloride hexahydrate in water to form a ferric chloride solution hexahydrate； b) dissolve an adequate amount of NaOH in water to form a NaOH solution； c) mixing the ferric chloride hexahydrate solution and the NaOH solution to form a solution with Fe (OH) 3 precipitate； d) maintain the pH of the solution with Fe (OH) 3 precipitate above 7.0； e) isolate the precipitate of Fe (OH) 3； f) wash the Fe (OH) 3 precipitate three times with water； g) suspend the precipitate of Fe (OH) 3 in water； h) add citric acid to the Fe (OH) 3 precipitate to form a ferric solution of organic acid； i) stir and heat the ferric organic acid solution at 90-100 ° C for 30 to 120 minutes； j) remove solids in the ferric solution of organic acid by adding citric acid； k) allow the ferric solution of organic acid to cool below 30 ° C； l) maintain the pH of the ferric organic acid solution between 0.8-1.5； m) filter the ferric organic acid solution to obtain a liquid filtrate； n) mix acetone and liquid filtrate to form ferric citrate, o) isolate ferric citrate, p) wash ferric citrate with acetone three times； and q) dry the ferric citrate.Una composición para el uso en el tratamiento de un trastorno caracterizado por una concentración sérica elevada de fosfato, comprendiendo la composición una cantidad de citrato férrico de grado farmacéutico efectiva para reducir las concentraciones séricas de fosfato, donde la cantidad administrada de citrato férrico de grado farmacéutico es de 2 gramos por día a 30 gramos por día y donde el citra
