The efficacy of ascorbic acid in suboptimal responsive anemic hemodialysis patients receiving erythropoietin: a meta-analysis.

To determine the impact of adjuvant ascorbic acid therapy on erythropoietin-hyporesponsive, anemic patients undergoing hemodialysis. The online databases of PubMed, Cochrane library, IPA, CINAHL, EMBASE, clinicaltrial.gov, WHO trial registry and PyschINFO were used. Studies comparing ascorbic acid to a control, with participants receiving erythropoietin and hemodialysis, and reported outcomes for hemoglobin or transferring saturation. Two independent researchers reviewed titles and abstracts to determine relevance and extracted study design, dose, duration, baseline values, and outcomes. Five studies met all the criteria and were used for final analysis. The calculated weighted mean difference between hemoglobin in the ascorbic acid group versus the control group was 0.96 g/dL (95% CI, 0.78 to 1.14). The calculated weighted mean difference between transferrin saturation in the ascorbic acid treatment group versus the control was 8.26% (95% CI, 6.59 to 9.94). Adjuvant ascorbic acid significantly raises hemoglobin levels in patients with erythropoietin hyporesponsiveness undergoing hemodialysis. The significant rise in transferrin saturation indicates that this positive effect on erythropoietin response may be due to increased iron utilization.