Daily vitamin C was tied to a meaningful drop in deaths among people with precancerous or low-risk blood cancers, and the same trial also showed fewer serious complications and calmer inflammation markers on the supplement. The signal comes from the EVITA phase 2 trial, published in CANCER, and gives researchers a clear reason to plan a larger confirmatory study.
The headline finding is an exploratory survival benefit. After about 33.6 months of follow-up, 11 of the 55 participants assigned to 1,000 mg of oral vitamin C per day had died, compared with 24 of the 54 participants assigned to placebo. That gap is what makes the trial worth attention, even though the primary endpoint was not met.
What the EVITA trial actually tested
EVITA was a randomized, double-blind, placebo-controlled study run at sites in Denmark and the United States. It enrolled 109 people with either clonal cytopenia of undetermined significance (CCUS) or lower-risk myeloid malignancies, conditions that can progress to leukemia.
Participants were randomly assigned to take 1,000 mg of oral vitamin C daily or a placebo for 12 months. The primary endpoint was whether vitamin C slowed the growth of abnormal blood cells. On that measure, the two groups looked similar at the end of treatment.
The interesting results showed up in the secondary and exploratory outcomes, not the primary one.
What changed for people taking vitamin C
Researchers tracked inflammation signaling and clinical events throughout the study.
- Fewer cases of anemia, pneumonia, acute aseptic arthritis, and internal bleeding.
- Changes in inflammatory markers that pointed in a favorable direction.
- A survival gap at follow-up: 11 deaths on vitamin C versus 24 on placebo.
The trade-off was more gastrointestinal side effects in the vitamin C group, something the authors flagged when weighing benefits against tolerability.
Why vitamin C was tested against blood cancer risk
Vitamin C boosts the activity of TET enzymes, proteins that help decide whether certain genes are switched on or off. Reduced TET activity shows up frequently in blood cancers, which is what made the supplement a plausible candidate to study rather than a folk remedy added on a hunch.
The Van Andel Institute-Stand Up To Cancer (VAI-SU2C) Epigenetics Dream Team led the EVITA trial to test exactly that mechanism in people whose disease had not yet turned into leukemia.
What the results do and do not mean
The primary endpoint of slowing abnormal cell growth was not met, so vitamin C is not yet a treatment for CCUS or low-risk myeloid malignancies. The survival benefit is an exploratory finding, the kind that needs a bigger, longer phase 3 trial to confirm before any guideline can change.
Researchers involved with the trial said the data support further study of whether and how vitamin C might help people with early-stage blood disorders, and the findings could inform strategies to prevent leukemia.
Practical takeaways right now
For anyone with CCUS or a lower-risk myeloid malignancy, this trial is a signal, not a recommendation. A few things are worth keeping in mind while the field waits for a confirmatory study:
- Do not start self-prescribing high-dose vitamin C on the basis of one phase 2 trial. The 1,000 mg dose used in EVITA is well above typical dietary intake and was given under medical supervision.
- Treat the survival number as hypothesis-generating, not as proof. Exploratory findings in smaller trials can shrink or disappear when a larger phase 3 study repeats the test.
- Watch for the phase 3 trial announcement. The clearest next step from this work is a larger, longer study designed to test the survival question directly.
The underlying science, that TET enzymes matter in blood cancer and vitamin C activates them, is solid enough that the next trial is being planned, not the first experiment.
FAQ
What did the EVITA trial find about vitamin C and blood disorders?
The phase 2 trial of 109 people with precancerous or low-risk blood cancers found that 1,000 mg of daily oral vitamin C did not slow abnormal cell growth but was linked to favorable changes in inflammation, fewer serious complications, and fewer deaths during follow-up compared with placebo.
How many people died in the vitamin C and placebo groups?
At a median follow-up of 33.6 months, 11 of 55 participants in the vitamin C group had died, compared with 24 of 54 participants in the placebo group. The researchers classified this as an exploratory finding, not a confirmed result.
Why is vitamin C being studied for blood cancer prevention?
Vitamin C increases the activity of TET enzymes, which help regulate whether certain genes are switched on or off. Reduced TET enzyme activity is common in some blood cancers, which led researchers to test whether supplementation could help people at risk of developing these diseases.
