Milk supplementation of the diet of postmenopausal Chinese women on a low calcium intake retards bone loss

Abstract

The Chinese diet is low in calcium (less than 500 mg/day on average), and previous observational studies have suggested an association between a low calcium intake and risk of hip and vertebral fracture. In this study, we randomly assigned 200 postmenopausal Chinese women (age range, 55-59 years) to receive 50 g of milk powder containing 800 mg of calcium per day or to a control group. The following are the mean percentage changes (and SEs) in height and bone mineral density (BMD) over 24 months: for height, -0.1 ± 0.2 cm in the milk supplementation group and -0.2 ± 0.1 cm in the control group; for BMD at the total hip, -0.06 ± 0.22% in the milk supplementation group and -0.88 ± 0.26% in the control group; for BMD at the spine (L1-L4), -0.56 ± 0.29% in the milk supplementation group and -1.5 ± 0.29% in the control group; for total body BMD, -0.32 ± 0.16% in the milk supplementation group and -1.2 ± 0.19% in the control group (p < 0.05 by analysis of covariance [ANCOVA] for repeated measures for height and BMD at all sites). The milk supplementation group had less loss in terms of both height and BMD than the control group (p < 0.05 by ANCOVA for repeated measures). Serum parathyroid hormone (PTH) concentration was lower and serum 25-hyroxyvitamin D [25(OH)D] level was higher in the milk supplementation group than the control group at 12 months (p < 0.05 by paired t-test). We conclude that supplementing the diet of postmenopausal Chinese women with high calcium milk powder retards bone loss.