White blood count; c-reactive protein; creatinine; calcium (total); free (ionized) calcium; phosphate; albumin; 25-hydroxyvitamin-D; 1-25-dihydroxyvitamin-D; homocysteine; cystatin C alphafetoin, osteoprotegerin; fibroblast growth factor 23 (FGF-23); globular arrest 1 (GLA-1)