Calcium intake influences the association of protein intake with rates of bone loss in elderly men and women.

What Was Tested

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

The objective of the present study was to determine whether supplemental calcium citrate malate and vitamin D influence any associations between protein intake and change in bone mineral density (BMD).

Why It Was Studied

There is currently no consensus on the effect of dietary protein intake on the skeleton, but there is some indication that low calcium intakes adversely influence the effect of dietary protein on fracture risk.

Who Took Part

The abstract describes 342 men taking part.

The age groups tagged for this paper are older adults, both men and women.

Associations between protein intake and change in BMD were examined in 342 healthy men and women (aged > or = 65 y) who had completed a 3-y, randomized, placebo-controlled trial of calcium and vitamin D supplementation.

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 and who got the comparison, which limits bias.

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

Protein intake was assessed at the midpoint of the study with the use of a food-frequency questionnaire and BMD was assessed every 6 mo by dual-energy X-ray absorptiometry.

What Was Measured

The subject headings attached to it are Absorptiometry, Photon, Bone Density, Calcium, Diet, Dietary Proteins, Energy Intake and Vitamin D.

What This Means in Plain Language

The paper is a randomized and placebo-controlled study of Vitamin D and Calcium in 342 men.

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

Its findings take up roughly 4 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2002 (The American journal of clinical nutrition), a journal based in United States.

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