Calcium and vitamin D supplementation and incident rheumatoid arthritis: the Women's Health Initiative Calcium plus Vitamin D trial.

What Was Tested

The paper reports a study of Vitamin D, K2, Magnesium and Zinc in the context of rheumatoid arthritis, published as a randomized controlled trial.

To determine whether calcium plus vitamin D supplementation (CaD) affects incidence of rheumatoid arthritis (RA).

Why It Was Studied

Incident RA cases were identified via self-report and validated rheumatic medication use.

The analysis included 32,435 women without the history of RA, of which 163 incident RA cases were identified over an average of 5.1 years.

Who Took Part

According to the abstract, 32,435 women were involved.

By PubMed's age tags, the people studied were middle-aged adults, older adults and people over 80, women only.

How the Study Was Run

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

Because people in this Vitamin D, K2, Magnesium and Zinc study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Some women received a placebo instead of Vitamin D, K2, Magnesium and Zinc, giving a reference point.

What Was Measured

The subject headings attached to it are Arthritis, Rheumatoid, Calcium Carbonate, Dietary Supplements, Incidence, Vitamin D and Women's Health.

What This Means in Plain Language

The paper is a randomized and placebo-controlled study of Vitamin D, K2, Magnesium and Zinc in 32,435 women in people with rheumatoid arthritis.

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

The publication is from 2012 (Rheumatology international), a journal based in Germany.

More context: the Vitamin D, K2, Magnesium and Zinc compound page, Rheumatoid arthritis research.