Daily Vitamin C Cuts Deaths by More Than Half in Blood Cancer Precursor Trial
A phase 2 trial found vitamin C linked to fewer deaths, less anemia, and better inflammatory markers in people with precancerous blood disorders.
Summary
A randomized, double-blind trial called EVITA tested daily 1,000 mg vitamin C in 109 people with precancerous or low-risk blood cancers. While vitamin C did not slow abnormal cell growth — the primary goal — it produced notable secondary benefits: fewer cases of anemia, pneumonia, and internal bleeding, plus favorable shifts in inflammatory signaling. Most strikingly, an exploratory survival analysis showed only 11 deaths in the vitamin C group versus 24 in the placebo group over nearly three years. Researchers attribute the potential mechanism to vitamin C's ability to activate TET enzymes, which regulate gene expression and are commonly suppressed in blood cancers. A larger phase 3 trial is needed before clinical recommendations can be made.
Detailed Summary
Vitamin C has long been known for supporting immune function, but a new clinical trial suggests it may also offer a survival advantage for people with early-stage blood disorders that can progress to leukemia. The EVITA trial, published in CANCER, a peer-reviewed journal of the American Cancer Society, enrolled 109 participants across Denmark and the United States, all of whom had either a precancerous blood condition or low-risk blood cancer.
Participants were randomized to receive either 1,000 mg of oral vitamin C daily or a placebo for 12 months, with a median follow-up of nearly three years. The primary endpoint — whether vitamin C slowed the growth of abnormal blood cells — showed no significant difference between groups. This was a clear null result on the main measure.
However, secondary and exploratory analyses told a more compelling story. People taking vitamin C experienced fewer serious complications including anemia, pneumonia, acute aseptic arthritis, and internal bleeding. Inflammatory signaling also shifted in directions associated with better outcomes. Most notably, only 11 deaths occurred in the vitamin C group compared to 24 in the placebo group over the follow-up period — a striking difference in an exploratory survival analysis.
The biological rationale centers on TET enzymes — cellular proteins that help regulate which genes are turned on or off. Vitamin C is known to boost TET enzyme activity, and reduced TET function is a hallmark of many blood cancers. This epigenetic mechanism gives researchers a plausible pathway through which vitamin C could interfere with cancer progression.
Researchers are cautious, emphasizing that these survival findings are exploratory and must be confirmed in a larger phase 3 trial before any recommendations change. Nonetheless, the signal is strong enough that a follow-up trial is now strongly motivated. For health-conscious adults, these findings add to a growing body of evidence supporting adequate vitamin C intake as potentially relevant to cancer interception and healthy aging.
Key Findings
- Vitamin C group had 11 deaths vs. 24 in placebo over ~3 years — a striking exploratory survival signal.
- Daily 1,000 mg vitamin C reduced serious complications including anemia, pneumonia, and internal bleeding.
- Vitamin C produced favorable inflammatory changes, a known marker of better long-term outcomes.
- The primary endpoint — slowing abnormal blood cell growth — showed no significant difference between groups.
- Mechanism may involve TET enzyme activation, which regulates gene expression suppressed in blood cancers.
Methodology
This is a news summary of a published phase 2 randomized, double-blind, placebo-controlled clinical trial (EVITA) in the peer-reviewed journal CANCER. The study enrolled 109 participants and is credibly sourced from Van Andel Institute and Rigshospitalet. Survival findings are exploratory and not pre-specified primary endpoints.
Study Limitations
The survival benefit is an exploratory, post-hoc finding in a small trial of 109 participants and should not be used to make clinical recommendations. Gastrointestinal adverse effects were higher in the vitamin C group, which needs further characterization. A larger, adequately powered phase 3 trial is essential to confirm or refute these findings.
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