Title

Effects of calcium and vitamin D supplementation on hip bone mineral density and calcium-related analytes in elderly ambulatory Australian women: A five-year randomized controlled trial

Document Type

Journal Article

Publisher

The Endocrine Society

Faculty

Computing, Health and Science

School

Exercise, Biomedical and Health Science

RAS ID

5630

Comments

This article was originally published as: Zhu, K., Devine, A., Dick, I. M., Wilson, S. G., & Prince, R. L. (2008). Effects of calcium and vitamin D supplementation on hip bone mineral density and calcium-related analytes in elderly ambulatory Australian women: A five-year randomized controlled trial. The Journal of Clinical Endocrinology & Metabolism, 93(3), 743-749. Original article available here

Abstract

This study shows that addition of vitamin D to calcium has long-term beneficial effects on bone mineral density in elderly women living in a sunny climate. While calcium halted hip bone turnover, it only did so for one year after treatment. Supplementation with vitamin D continued the reduction in hip bone turnover for three to five years. Context: Effects of long-term calcium, with or without vitamin D, on hip bone mineral density (BMD) and bone turnover in sunny climates have not been reported. Objective: The aim was to evaluate the effect of vitamin D added to calcium supplementation on hip dual-energy x-ray absorptiometry BMD and calcium-related analytes. Design, Setting, and Participants: The study was a 5-yr randomized, controlled, double-blind trial of 120 community-dwelling women aged 70–80 yr. Interventions: The interventions were 1200 mg/d calcium with placebo vitamin D (Ca group) or with 1000 IU/d vitamin D2 (CaD group), or double placebo (control). Main Outcome Measures: Hip BMD, plasma 25-hydroxyvitamin D, biomarkers of bone turnover, PTH, and intestinal calcium absorption were measured. Results: Hip BMD was preserved in CaD (−0.17%) and Ca (0.19%) groups but not controls (−1.27%) at yr 1 and maintained in the CaD group only at yr 3 and 5. The beneficial effects were mainly in those with baseline 25-hydroxyvitamin D levels below the median (68 nmol/liter). At yr 1, compared with controls, the Ca and CaD groups had 6.8 and 11.3% lower plasma alkaline phosphatase, respectively (P ≤ 0.02), and 28.7 and 34.5% lower urinary deoxypyridinoline to creatinine ratio, respectively (P ≤ 0.05). At 5 yr, this suppression was maintained only in the CaD group. CaD reduced PTH at 3 and 5 yr cf. controls (27.8 and 31.3%, P ≤ 0.005) in those with baseline PTH levels above the median (3.6 pmol/liter). Therapy did not affect intestinal calcium absorption at high carrier loads. Conclusions: Addition of vitamin D to calcium has long-term beneficial effects on bone density in elderly women living in a sunny climate, probably mediated by a long-term reduction in bone turnover rate.

DOI

10.1210/jc.2007-1466

 

Link to publisher version (DOI)

10.1210/jc.2007-1466