Vitamin C Associated With Fewer Deaths in Patients With Blood Disorder, Trial Finds - Video

Daily vitamin C did not slow abnormal blood cell growth in people with precancerous blood disorders or low-risk blood cancers, but the supplement was linked to favourable inflammatory changes and a possible survival benefit, according to a phase 2 clinical trial.

Published in CANCER, the EVITA trial included 109 participants in Denmark and the United States. They had either a blood disorder that could progress to cancer or a low-risk blood cancer.

Participants were randomly assigned to receive either 1,000 mg of oral vitamin C daily or a placebo for 12 months. The trial was randomised, double-blind and placebo-controlled.

The main outcome was the effect of vitamin C on the growth of abnormal blood cells. Researchers found no meaningful difference between the vitamin C and placebo groups, indicating that supplementation did not slow abnormal cell growth over the study period.

However, vitamin C was associated with changes in inflammatory signalling that researchers considered potentially favourable. Participants receiving vitamin C also experienced fewer cases of anaemia, pneumonia, acute aseptic arthritis and internal bleeding. Gastrointestinal problems, however, were more common in the vitamin C group.

During a median follow-up of 33.6 months, 35 participants died. Of these deaths, 11 occurred among people assigned to vitamin C, compared with 24 in the placebo group.

An exploratory analysis suggested that participants receiving vitamin C had better survival during follow-up. However, researchers stressed that this was not the primary outcome and the finding needs confirmation in a larger phase 3 trial.

Vitamin C can increase the activity of TET enzymes, proteins involved in regulating gene activity. Reduced TET activity is common in some blood cancers, providing a biological rationale for studying vitamin C in people with early-stage disease.

The researchers say the findings are encouraging but do not support using high-dose vitamin C as a treatment for blood cancer or precancerous disorders at this stage. Larger clinical trials are needed to determine whether vitamin C can improve survival or provide other meaningful clinical benefits in this population.

REFERENCE: Stine Ulrik Mikkelsen, et al.; Oral vitamin C supplementation in patients with clonal cytopenia of undetermined significance or lower‐risk myeloid malignancies: Results from EVITA, a phase 2 randomized, placebo‐controlled trial. Cancer, 2026; 132 (19) DOI: 10.1002/cncr.70549