September 21, 2026

expert reaction to phase 2 trial looking at oral vitamin C supplementation in patients with pre-cancer blood disorders

A study published in Cancer looks at oral vitamin C supplementation in patients with pre-cancer blood disorders.

Dr Manoj Raghavan, Honorary Associate Professor, University of Birmingham, Consultant Haematologist, University Hospitals Birmingham NHS Foundation Trust, said:

“The press release reflects the science accurately; it is good quality research, and the trial is well designed. The study challenges preconceptions as to the effects of vitamin C in not changing clonality, which was the primary end point of the study. The improvement in overall survival is unexpected and changes ideas about the efficacy of vitamin C. The authors have looked for confounders for impact on overall survival and whether vitamin C concentration has any effect. The major finding of improved overall survival was an exploratory post-hoc analysis – not pre-determined, which weakens, but does not negate the finding in this phase 2 trial; further studies are still required. Secondary endpoints were biological – serum concentration of vitamin C, which was met; methylation and hydroxymethylation levels, cytokine and chemokine levels showed no correlation with treatment. Clinical secondary endpoints (disease progression and haematological improvement) were not different between treatment and placebo.”

Dr John Riches, Clinical Reader in Cancer Immuno-metabolism, Barts Cancer Institute, St Bartholomew’s Hospital, said:

“This is a well-designed randomised, placebo-controlled trial, which is a real strength. However, the main aim of the study was not achieved: vitamin C did not significantly slow the growth of the abnormal blood-cell clones. The apparent improvement in survival is interesting, but this was an unexpected finding in a relatively small study that was not designed to test whether vitamin C helps people live longer. The results are therefore interesting enough to justify a larger trial, but we do not yet have good enough evidence to say that vitamin C improves outcomes or should change clinical practice in these early stage blood cancers.”

‘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’ by Stine Ulrik Mikkelsen et al. was published in Cancer at 08:01 UK Time on Monday 21 September. 

DOI: 10.1002/cncr.70549

Declared interests

Dr Manoj Raghavan:

“Research funding: Novartis, via UKCHART (UKCHART – The Royal Wolverhampton NHS Trust)

Speaker fees: Pfizer UK

Advisory Board: GSK

Sponsorship for travel to conferences: Novartis UK, Otsuka Pharmaceuticals”

Dr John Riches: “I don’t have any conflicts of interest with regard to this study.”