Unclear
Calcium pills
calcium supplements. Vitamins & minerals.
- Verdict
- UnclearThere isn't enough human evidence to say either way.
- 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
What the evidence shows
The World Cancer Research Fund rates calcium supplements as probably lowering colorectal cancer risk, but the National Cancer Institute says it isn't known whether they do. In a randomized trial of 2,259 people who had polyps removed, 1,200 mg of calcium a day did not significantly reduce new polyps (45.3% vs 47.6%).
What to do
Don't take calcium pills just to prevent colorectal cancer. Calcium from food, including dairy, is fine.
Sources
To take it to your doctor, print this page.
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.