Studies in rats with renal ablation indicate that anemia lessens, whereas its vigorous correction with recombinant human erythropoietin (r-HuEPO) worsens systemic and glomerular hypertension, factors known to promote progression of chronic renal failure (CRF). However, in human studies, use of r-HuEPO in predialysis patients has not been associated with worsening renal function, provided blood pressure control is achieved. Histological evidence of bone disease is common in early renal failure, and deficits in calcitriol synthesis seem to be an important factor in the pathogenesis of secondary hyperparathyroidism (HPTH) in early CRF. Reports to data, on the use of low dose active vitamin D metabolites in predialysis patients, indicate either a reversible decline or no decline in renal function. Adynamic bone disease, however, may ensure during such therapy if excessive reductions in serum intact parathyroid hormone concentrations occur. Recent data suggest that chronic metabolic acidosis decreases albumin synthesis, increases muscle proteolysis, and induces negative nitrogen balance in patients with CRF. Despite these experimental data, the clinical relevance of correction of metabolic acidosis in end-stage renal disease (ESRD) is still not defined. Even though therapy of metabolic acidosis in the adult patient with CRF remains conjectural at this time, reports indicate that its correction might lead to healing of osteomalacia and osteopenia, and possibly may decrease protein degradation and improve growth in children with CRF.