High-Dose Vitamin C Supplementation in Patients Undergoing Allogeneic Hematopoietic Stem Cell Transplantation: A Pilot Randomized, Triple-Blind, Placebo-Controlled Trial Publisher Pubmed



Heidari S ; Shahrami B ; Rad S ; Sadeghi K ; Sharifi Aliabadi L ; Hadjibabaei M ; Vaezi M
Source: Supportive Care in Cancer Published:2026

Abstract

Purpose: Allogenic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment for hematological disorders but often results in micronutrients deficiency and complications. Vitamin C, a potent antioxidant, may improve endothelial function, tissue protection, and immune recovery. This study evaluated the effects of early high-dose vitamin C supplementation on plasma vitamin C levels and post-HSCT complications. Methods: In this pilot, triple-blind, placebo-controlled trial, 31 adult allo-HSCT patients were randomized to receive intravenous vitamin C (50 mg/kg/day) or placebo from day + 1 to + 14, followed by oral vitamin C (500 mg/day) or placebo until day + 100. Plasma vitamin C levels were measured at days 0, + 7, + 15, and discharge. Patients were monitored for post-HSCT complications until day + 100. Results: Plasma vitamin C levels were significantly higher in the vitamin C group at all time points (P < 0.001). Trends toward reduced acute graft-versus-host disease (33% vs. 44%), lower oral mucositis severity (46.6% vs. 62.5%), and shorter duration (7.5 ± 3.6 vs. 9.1 ± 3.7 days) were observed, though not statistically significant. No significant adverse events were reported. Conclusion: High-dose vitamin C effectively corrected plasma levels, and while trends toward reduced complications were observed in allo-HSCT patients, larger trials are needed to confirm these findings. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2026.