Introduction  1 2 3 3 2 4 10 3 Subjects and methods Patients and study design 3 3 3 3 3 3 3 3 3 3 3 3 3 urea 11 , 3 3 3 3 3 3 3 3 3 Statistical analysis The laboratory values were expressed as mean [± one standard deviation (SD)]. t P Results 3 3 3 1 2 3 1 4 urea 3 3 Table 1 Patients’ data in terms of the use of phosphate-binders and vitamin D before the washout period  3 n 3 n Vitamin D 11/25 8/21 Phosphate binders 25/25 21/21      3 19 16     Sevelamer 2 4     CaCO3 + sevelamer 4 1 Table 2 Mean serum values at baseline  3 3 P t Age (years) 63.23 65.32 P SD 12.19 11.68 a 9.42 9.14 P SD 0.54 0.43 Phosphorous (mg/dl) 6.63 6.58 P SD 0.86 0.88 2 62.62 60.08 P SD 10.36 8.35 Magnesium (mg/dl) 2.38 2.36 P SD 0.28 0.29 ALP (IU/l) 76 86 P SD 37 35 Intact PTH (pg/ml) 316 296 P SD 182 157 SD, Standard deviation; ALP, alkaline phosphatase; PTH, parathyroid hormone; ns, not significant a Table 3 Mean values at 6 months  3 3 P t a 8.97 9.72 t SD 0.57 0.42 P Phosphorous (mg/dl) 5.12 5.28 t SD 0.70 0.74 P 2 46.04 51.38 t SD 7.65 7.75 P Magnesium (mg/dl) 2.59 2.40 t SD 0.43 0.41 P ALP (IU/l) 89 84 t SD 28 26 P Intact PTH (pg/ml) 251 212 t SD 118 198 P a Fig. 1 sP  Fig. 2 sCa  Fig. 3 SCa × P  Fig. 4 siPTH  3 3 3 3 3 3 a 4 3 3 P 3 3 P 2 3 3 3 P 4 3 3 P 3 2 P 5 Table 4 Average serum values during months 1–6 of the follow-up period  3 3 P t a 9.13 9.60 P SD 0.53 0.45 Phosphorous (mg/dl) 5.47 5.29 P SD 0.81 0.93 2 50.35 50.70 P SD 7.75 8.07 2 2.57 2.41 P SD 0.41 0.32 ALP (IU/l) 88 80 P SD 32 27 Intact PTH (pg/ml) 285 231 P SD 161 177 a Table 5 Patients with laboratory values within the Kidney Disease Outcomes Quality Initiative (K/DOQI) guideline range at 6 months  3 n 3 n 2 P Calcium  17/23 (73.91) 5/20 (25) 2 P Phosphorous 17/23 (73.91) 13/20 (65) 2 P Ca × P product 20/23 (86.95) 14/20 (70) 2 P PTH 11/23 (47.82) 8/20 (40) 2 P 3 3 P 2 3 3 P  4 P 2 3 3 2 P 5 3 3 2 4 3 2 2 3 2 2 P 1 2 2 3 2 2  3 P 4 2 2 P 3 P 5 3 3 P 2 3 3 P 4 P 3 3 3 2 P 3 3 3 3 2 P 3 3 P 3 3 5 2 P 3 3 P 4 P 3 3 3 Discussion 3 3 4 5 3 3 3 3 3 6 3 3 7 10 12 3 3 3 3 3 3 13 14 15 16 3 1 In terms of the biochemical findings, the main difference between the two groups was the levels of serum calcium. Hypercalcemia is the price one has to pay for adequate phosphate-binding control with calcium-containing binders; the absence of hypercalcemia is the major advantage of magnesium-based phosphate-binders. 3 17 3 2 2 3 4 5 3 18 19 20 21 22 23 24 25 26 27 28 29 30 3 3 3 3 4 3 3 P 3 31 4 3 3 3 3 . 3 The limitations of our study are: (1) it is a single-center study, although this has also a number of advantages; (2) the number of the participant patients was not large, although it is one of the largest groups reported to date; (3) the allocation of the patients to the two regimens was only partially random; (4) the relatively low starting serum phosphate level in conjunction with the no vitamin D use means that the patients were not typical of most HD patients; (5) we did not obtain data on the patients’ bone metabolism markers. 3 3 3