Comment in:
Am J Clin Nutr. 2002 Apr;75(4):609-10.

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

Dawson-Hughes B, Harris SS.

Calcium and Bone Metabolism Laboratory, Jean Mayer US Department of
Agriculture Human Nutrition Research Center on Aging, Tufts University,

BACKGROUND: 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.
OBJECTIVE: 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). DESIGN:
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. 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. RESULTS: The mean (+/-SD) protein
intake of all subjects was 79.1 +/- 25.6 g/d and the mean total calcium
intakes of the supplemented and placebo groups were 1346 +/- 358 and 871 +/-
413 mg/d, respectively. Higher protein intake was significantly associated
with a favorable 3-y change in total-body BMD in the supplemented group (in
a model containing terms for age, sex, weight, total energy intake, and
dietary calcium intake) but not in the placebo group. The pattern of change
in fem{*filter*}neck BMD with increasing protein intake in the supplemented group
was similar to that for the total body. CONCLUSION: Increasing protein
intake may have a favorable effect on change in BMD in elderly subjects
supplemented with calcium citrate malate and vitamin D.

Publication Types:
Clinical Trial
Randomized Controlled Trial

PMID: 11916767 [PubMed - indexed for MEDLINE]