Pyridoxine intake and cancer risk across many studies
What it found
Higher vitamin B6 (pyridoxine) intake and higher blood levels of its active form were linked to lower risk of colorectal and pancreatic cancer in observational studies.
The evidence for other B vitamins was mixed.
What they found
Studies in people
Colorectal cancer and B6
A meta-analysis of 28 observational studies found that higher dietary vitamin B6 intake was linked to lower colorectal cancer risk. Higher blood levels of pyridoxal 5-phosphate, the active form of B6, showed a stronger link. The link was clearest in women and for colon cancer specifically.
Colorectal cancer and riboflavin
An observational meta-analysis found that higher vitamin B2 (riboflavin) intake was linked to lower colorectal cancer risk.
Colorectal cancer and folate
Randomised trials of folic acid supplements found no clear effect on colorectal cancer risk. In contrast, prospective studies of folate from food found a lower risk. The authors suggest differences in how intake was measured and background fortification may explain this.
Colorectal cancer and B12
A dose-response meta-analysis found a modest link between higher vitamin B12 intake and lower risk of colorectal adenoma and cancer. The link was stronger for B12 from food than for total B12.
Oesophageal cancer
Higher dietary intake of vitamin B6 and folate was linked to lower oesophageal cancer risk. In contrast, higher vitamin B12 intake was linked to a small increase in risk of oesophageal adenocarcinoma.
Pancreatic cancer and B6
Strong links were found between higher vitamin B6 intake and lower pancreatic cancer risk, both for B6 from food and for blood levels of its active form. No significant links were found for vitamin B12.
Breast and ovarian cancer
No overall link was found between folate intake and breast cancer risk, though a J-shaped pattern was seen with lowest risk at 200 to 320 micrograms per day and higher risk above 400 micrograms per day. No significant link was found between folate intake and ovarian cancer.
Melanoma
One meta-analysis of randomised trials suggested folic acid supplements were linked to lower melanoma risk. Larger pooled analyses of trials with more than 50,000 participants did not confirm this and found no link.
What the authors conclude
“This structured narrative synthesis suggests that vitamin B6 (pyridoxine) and its active biomarker pyridoxal 5′-phosphate are inversely associated with the risk of gastrointestinal cancers, particularly colorectal and pancreatic cancer.”
Also in their conclusions
- They conclude that vitamin B6 (pyridoxine) and its active biomarker pyridoxal 5-phosphate are inversely associated with the risk of gastrointestinal cancers, particularly colorectal and pancreatic cancer.
- They state that the current body of evidence does not support the use of high-dose B-vitamin supplementation for primary cancer prevention in the general population.
- They advise that these findings are consistent with the importance of achieving adequate B-vitamin intake through balanced dietary patterns, while calling for further well-designed prospective studies and targeted trials.
How it was done
The authors wanted to summarise and put into clinical context the evidence on whether intake of vitamins B2, B6, B12 and folate is linked to the risk of certain cancers, because findings across studies have been inconsistent.
They searched PubMed up to 2 September 2025 and included 45 studies in a structured narrative review. They prioritised meta-analyses of observational studies and included randomised controlled trials of B-vitamin supplements when relevant.
What it can’t tell you
- Most of the evidence comes from observational studies, which can show a link but cannot prove that B vitamins cause or prevent cancer.
- The studies used different ways to measure B-vitamin intake and looked at different populations, so the results cannot be directly compared.
- The review did not perform new statistical analyses, so it cannot provide a single combined estimate of effect.
Who paid
- Conflicts
- The authors(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
- Authors work at
- University of Urbino Carlo Bo, Italy; Francesca Pirozzi Foundation ETS, Italy; University of Insubria, Italy
The paper
- Title
- B vitamins intake and cancer risk: a structured narrative review of evidence on riboflavin, pyridoxine, cobalamin and folate
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Bertuccioli A, Palazzi CM, Massaro IA, et al (2026). B vitamins intake and cancer risk: a structured narrative review of evidence on riboflavin, pyridoxine, cobalamin and folate. Pathology oncology research. doi:10.3389/pore.2026.1612380Free full textPubMed 42403423DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error