Association between vitamin C deficiency and dialysis modalities

Aim: We designed a cross-sectional study to investigate plasma vitamin C level in patients who underwent maintenance haemodialysis (MHD) and continuous ambulatory peritoneal dialysis (CAPD) to explore whether there is a difference in vitamin C deficiency between MHD patients and CAPD patients. Methods: This investigation included 382 dialysis patients without vitamin C supplement before the study. Demographic characteristics, laboratory tests, ascorbic acid and total plasma vitamin C level were measured. A linear regression model was built to explore the association between vitamin C deficiency and dialysis modalities after adjusting for age, dialysis vintage, gender, Charlson index, modality of dialysis and hsCRP. Results: The range of plasma vitamin C level was from 0.48 mu g/mL to 31.16 mu g/mL. 35.9% (n = 137) patients had severe vitamin C deficiency (<2 mu g/mL). Plasma vitamin C level was inversely associated with age and dialysis vintage. After age and dialysis vintage were adjusted, vitamin C deficiency was associated with MHD. R square for model fitting was relatively low, which implied that there were other vitamin C influencing factors not included in the model. Conclusions: Vitamin C deficiency is common in dialysis patients, especially in patients treated with MHD.