Reduced Plasma Ascorbate and Increased Proportion of Dehydroascorbic Acid Levels in Patients Undergoing Hemodialysis.
Level 3 - non-randomized controlled study
Non-randomized comparative observational study with pre- and post-dialysis measurements
PubMed 34685394 · doi:10.3390/life11101023
What was done
Researchers measured plasma ascorbate and dehydroascorbic acid (DHA) levels in two groups: non-hemodialysis-dependent chronic kidney disease (CKD stage G3-G5) patients, and CKD stage G5D hemodialysis patients assessed both before and after a dialysis session. Sample size calculation was performed using G-Power software.
What was found
Pre-dialysis plasma total ascorbate levels (including DHA) were 56% lower in hemodialysis patients compared to non-hemodialysis CKD patients. A single hemodialysis session led to an additional 40% reduction in plasma total ascorbate levels and increased the proportion of DHA from 37% to 55%.
Why it matters
This study shows that hemodialysis patients have substantially depleted total ascorbate compared to non-dialysis CKD patients, and that the dialysis process itself further depletes ascorbate while increasing the relative fraction of its oxidized form.
Limits
The abstract does not report the total sample size (n), absolute concentration values, standard deviations, confidence intervals, or p-values. Confounders such as dietary vitamin C intake and clinical outcomes were not described.
Cited by
- supports A single dialysis session in patients with renal failure decreases plasma vitamin C levels by roughly half.