Calcium for Colorectal Cancer

Calcium modestly reduces recurrence of conventional adenomas in trials, but one large study found an increase in serrated polyps.

Overview

Calcium modestly reduces recurrence of conventional adenomas in trials, but one large study found an increase in serrated polyps.

Verdict

Mixed evidence

Not recommended as chemoprevention — the balance of effects is unresolved.

How It Works

Calcium binds bile acids and free fatty acids in the colonic lumen, reducing their proliferative effect on epithelium, and may directly promote differentiation of colonocytes.

Dosing & Protocol

Typical dose

Recommended dose: No recommended chemopreventive dose; meet requirements from diet
Expected timeframe: Trials measured outcomes over 3-5 years.

Protocol

form: Dietary calcium preferred
notes: Not recommended as chemoprevention
duration: n/a
starting dose: Meet the RDA from food

Evidence

What the studies say

The Calcium Polyp Prevention Study found supplemental calcium reduced recurrent adenoma risk by roughly 15-20% over four years. However, a later analysis of the Vitamin D/Calcium Polyp Prevention Study reported an increased risk of sessile serrated adenomas six to ten years after supplementation, a lesion type with its own malignant potential. Combined with cardiovascular concerns raised about calcium supplements at high doses, the case for using calcium as chemoprevention has weakened considerably. Dietary calcium carries no comparable concern.

Prolonged effect of calcium supplementation on risk of colorectal adenomas in a randomized trial

Score: 8/10

2007

rct

n=930

Grau MV, Baron JA, Sandler RS +2 more

930 subjects with a previous colorectal adenoma were randomly assigned ... to receive placebo or 1200 mg of elemental calcium daily for 4 years

View source

Safety

Caveats

Supplemental calcium above 1000mg daily has been associated with kidney stones and, in some analyses, cardiovascular events. Possible increase in serrated polyps.

Less likely to help if

People meeting calcium requirements from diet already.

Medical Disclaimer

The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.