Effect of vitamin C on immune reconstitution after bone marrow transplantation

Background: Vitamin C is an essential nutrient for the adequate function and maturation of the immune system. In vitro studies show that the development, proliferation, and functioning of T cells requires vitamin C, especially for natural killer (NK) cells. Their deficiency during the acute phase post-transplantation could cause greater morbidity and mortality in these patients. A prospective clinical trial using high-dose vitamin C was performed to determine if vitamin C supplementation improves reconstitution of NK lymphocytes after hematopoietic stem cell transplantation (HSCT). Materials and methods: We enrolled 24 patients who underwent autologous HSCT for multiple myeloma and lymphoma. Patients were randomized to receive standard treatment or standard treatment plus 20 g vitamin C once daily (1 - 10 days) and 500 mg twice daily (11 - 100 days) after transplantation. Results: NK and CD3(+) lymphocytes showed an increase from days +30 to +100 only in the vitamin C-treated group. Patients in the vitamin C group had a lower frequency of infections. No severe adverse events were reported. Conclusion: Our results suggest that high-dose vitamin C supplementation is an effective and safe therapeutic option to decrease the frequency of infections and enhance immune reconstitution after HSCT.