149 patients with estimated glomerular filtration rates < 60 mL/min/1 .73 m ( 2 ) , iron deficiency anemia ( hemoglobin , 9.0-12 .0 g/dL ; transferrin saturation [ TSAT ] 30 % , serum ferritin 300 ng/mL ) , and serum phosphate levels 4.0 to 6.0 mg/dL .