Vitamin D deficiency is implicated in reduced serum albumin concentrations in patients with end-stage renal disease.

The mortality rate in hemodialysis patients remains extremely high, and reduced serum albumin concentration resulting from malnutrition is the strongest predictor of mortality and morbidity. Several inflammatory cytokines involved in malnutrition, including interleukin-1, interleukin-6, and tumor necrosis factor-alpha, are modulated by 1,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)], of which synthesis is impaired in end-stage renal disease. We evaluated whether 1,25-(OH)(2)D(3) deficiency might be involved in reduced serum albumin concentrations. Fifty-one predialysis uremic patients about to begin hemodialysis therapy were divided into groups with serum 1,25-(OH)(2)D(3) concentrations less than 18 pg/mL (low-D(3) group; n = 39) and concentrations of 18 pg/mL or greater (normal-D(3) group; n = 12). Serum albumin concentrations before the initiation of hemodialysis treatment were compared between the two groups. Furthermore, the effect of supplementation with active forms of vitamin D during 4 months of hemodialysis treatment on serum albumin concentrations was retrospectively evaluated in the low-D(3) group. Serum albumin concentrations in the low-D(3) group were significantly less than those in the normal-D(3) group (3.58 +/- 0. 50 versus 3.82 +/- 0.10 g/dL; P = 0.034). Considering all patients, a significant positive correlation between serum concentrations of albumin and 1,25-(OH)(2)D(3) was noted (r = 0.417; P = 0.0023). Supplementation with active forms of vitamin D significantly increased serum albumin concentrations in the low-D(3) group from 3. 61 +/- 0.12 to 3.79 +/- 0.13 g/dL (P = 0.0067). These findings indicate that reductions in serum albumin concentrations may be attributed, at least in part, to vitamin D deficiency in patients with end-stage renal disease.