Calcium plus vitamin D supplementation has limited effects on femoral geometric strength in older postmenopausal women: the Women's Health Initiative.

What Was Tested

The paper reports a study of Vitamin D, K2, Magnesium and Zinc, published as a randomized controlled trial.

Random effects models were used to test the average differences in hip BMD and geometry between intervention and placebo.

Why It Was Studied

Hip structural analysis software measured BMD and strength parameters on DXA scans at three regions: femoral narrow neck, intertrochanter, and shaft.

Who Took Part

The abstract describes 1,970 women taking part.

PubMed indexes the participants as middle-aged adults and older adults, women only.

How the Study Was Run

The design is described as randomized, double-blind and placebo-controlled.

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

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.

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

What Was Measured

Hip structural analysis software measured BMD and strength parameters on DXA scans at three regions: femoral narrow neck, intertrochanter, and shaft.

Topics PubMed links to this paper include Body Constitution, Bone Density, Calcium, Compressive Strength, Dietary Supplements, Drug Combinations and Femur.

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 1,970 women.

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

The publication is from 2011 (Calcified tissue international), a journal based in United States.

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