Calcium plus vitamin D supplementation and the risk of nonmelanoma and melanoma skin cancer: post hoc analyses of the women's health initiative randomized controlled trial.

What Was Tested

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

In light of inverse relationships reported in observational studies of vitamin D intake and serum 25-hydroxyvitamin D levels with risk of nonmelanoma skin cancer (NMSC) and melanoma, the researchers evaluated the effects of vitamin D combined with calcium supplementation on skin cancer in a randomized placebo-controlled trial.

Who Took Part

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

How the Study Was Run

The researchers set it up as a randomized and placebo-controlled study.

Random assignment meant chance, not the researchers, decided who got Vitamin D, K2, Magnesium and Zinc and who got the comparison, which limits bias.

The comparison arm used a placebo, so changes seen with Vitamin D, K2, Magnesium and Zinc could be set against what happens without it.

NMSC and melanoma skin cancers were ascertained by annual self-report; melanoma skin cancers underwent physician adjudication.

What Was Measured

PubMed files the paper under topics including Calcium, Dietary, Cholecalciferol, Confounding Factors, Epidemiologic, Dietary Supplements, Incidence, Kaplan-Meier Estimate and Melanoma.

What This Means in Plain Language

The paper is a randomized and placebo-controlled study of Vitamin D, K2, Magnesium and Zinc.

The abstract goes on to report its results in about 5 sentences; this page does not restate them, so read the paper for the findings and their limits.

The publication is from 2011 (Journal of clinical oncology : official journal of the American Society of Clinical Oncology), a journal based in United States.

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