[1] Univ Kentucky, Med Ctr, Div Nephrol Bone & Mineral Metab, Lexington, KY 40536 USA
[2] Hosp Curry Cabral, Dept Nephrol, Lisbon, Portugal
[3] Univ Porto, Nephrol Res & Dev Unit, P-4100 Oporto, Portugal
[4] Univ Porto, Sch Med, P-4100 Oporto, Portugal
[5] FMC Torres Vedras, Torres Vedras, Portugal
[6] FMC Entrocamento, Entrocamento, Portugal
[7] Unidade Hemodialise Sta Casa Mesericordia Vila Ve, Guimaraes, Portugal
[8] Tagus Dial Barreiro FMC, Tagus Dial Barreiro, Barreiro, Portugal
[9] Ctr Hemodialise Sta Casa Mesericordia Vila Verde, Vila Verde, Portugal
[10] HPA, Almada, Portugal
[11] Genzyme Europe Res, Cambridge, England