Positive results for Vitamin C in leukemia patients
Results from a Phase II clinical trial suggest that taking vitamin C supplements may be associated with improved survival chances in individuals with blood disorders that can progress to cancer, or with low-risk forms of blood cancers.
Researchers from the Van Andel Institute in the United States, in collaboration with Copenhagen University Hospital in Denmark, described the findings as promising, emphasizing the need to test them in a larger clinical trial. The results were published today in the journal CANCER, published by the American Cancer Society.
The study is based on the role of vitamin C in enhancing the activity of cellular proteins known as TET enzymes, which help regulate gene function by controlling their activation or deactivation. Reduced activity of these enzymes is a common factor in the development of certain blood cancers, prompting researchers to test whether vitamin C intake could influence the disease course in people at risk of developing these cancers.
The trial included 109 patients in Denmark and the United States who had either a blood disorder that could progress to cancer or a low-risk form of leukemia. Participants were randomly assigned to two groups; the first group, comprising 55 patients, received a daily oral dose of 1,000 milligrams of vitamin C, while 54 patients received a placebo. Treatment continued for 12 months.
No difference was observed between the groups in the study’s primary endpoint, which was the growth rate of pre-cancerous or cancerous cells, meaning the trial did not demonstrate that vitamin C slows the growth of these cells.
However, researchers observed changes in inflammation-related signaling among participants who took vitamin C, and these changes were consistent with indicators associated with better health outcomes. Some complications were also less common in the vitamin C group, including anemia, pneumonia, acute aseptic arthritis, and internal bleeding, whereas gastrointestinal issues were more common compared to the placebo group.
During a follow-up period with a median of 33.6 months, or approximately three years, 35 deaths were recorded among participants, including 24 deaths in the placebo group and 11 deaths in the vitamin C group.
An exploratory analysis of these data indicated that participants who received vitamin C were more likely to survive during the follow-up period compared to those who received the placebo. However, the researchers emphasized that this finding was exploratory and not among the trial’s primary endpoints, and therefore cannot be considered definitive evidence that vitamin C prolongs survival or prevents the progression of leukemia.
The researchers stated that the results provide a basis for continuing to study whether vitamin C may benefit individuals with certain pre-cancerous blood disorders or early-stage cancers, as well as investigating the mechanisms that may explain this potential effect.
The team concluded that the findings suggest a potential benefit of vitamin C for some individuals at risk of developing blood cancers, but confirming this benefit requires a Phase III clinical trial involving a larger number of patients.
