Folic acid
high-dose pills to prevent polyps. Vitamins & minerals.
- Verdict
- May raise riskSome studies point to higher risk, but it isn't confirmed.
- How sure
- Rung 2 · LimitedFew, small or conflicting human studies, or only indirect measures such as blood markers.
The rung shows how sure the science is, not how big the effect is. How to read these ratings
Cancers affected
Colorectal polyps, in people who've had them
What the evidence shows
In a trial of 1,021 people who'd had colorectal adenomas (polyps), 1 mg of folic acid a day didn't prevent new ones. People taking it tended to have more advanced polyps and more people had three or more (9.9% vs 4.3%). The researchers said the findings weren't definitive.
What to do
Don't take high-dose folic acid to prevent colon polyps. If you take it for another reason, such as pregnancy, keep following your doctor's advice.
Sources
Spotted an error? Tell us and we’ll check it against the sources.
Step by step
For the whole picture, from prevention and screening to treatment and life after, see the colorectal cancer page.