Calcium plus vitamin D supplementation and the risk of colorectal cancer.

What Was Tested

This randomized controlled trial looks at Vitamin D, K2, Magnesium and Zinc.

Who Took Part

The abstract describes 36,282 women taking part.

The age groups tagged for this paper are middle-aged adults and older adults, women only.

How the Study Was Run

In design terms this was a randomized, double-blind and placebo-controlled study.

The women were allocated by chance, so the Vitamin D, K2, Magnesium and Zinc group and the comparison group should start out alike.

Neither the women nor the staff measuring them knew who was on Vitamin D, K2, Magnesium and Zinc, so expectations could not easily colour the readings.

A placebo (an inactive look-alike) gave the Vitamin D, K2, Magnesium and Zinc group a baseline to be compared against.

The incidence of pathologically confirmed colorectal cancer was the designated secondary outcome.

Baseline levels of serum 25-hydroxyvitamin D were assessed in a nested case-control study.

What Was Measured

PubMed files the paper under topics including Adenocarcinoma, Calcium, Calcium Carbonate, Colonic Polyps, Colorectal Neoplasms, Drug Combinations and Incidence.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Vitamin D, K2, Magnesium and Zinc in 36,282 women.

With several hundred people or more, it is a fairly large study for this kind of research.

Its findings take up roughly 6 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2006 (The New England journal of medicine), a journal based in United States.

More context: the Vitamin D, K2, Magnesium and Zinc compound page, all human trials.