Bone density in healthy men after cessation of calcium supplements: 20-month follow-up of a randomized controlled trial

Abstract

Summary

Bone density has been followed up for 20 months following completion of a trial which compared calcium 1,200 mg/day with placebo, in normal older men. Following cessation of calcium supplements, there is a small residual benefit in total body bone density, but not at the hip or spine.

Introduction

Calcium supplements, or supplements of calcium-rich foods, have a positive effect on bone mineral density (BMD). However, it is uncertain whether there are any residual benefits of calcium on BMD following cessation of supplementation.

Methods

In a previously published study, 323 healthy men were randomized to receive elemental calcium 600 mg/day (n = 108), calcium 1,200 mg/day (n = 108), or placebo (n = 107) over 2 years. Consenting men from the placebo and calcium 1,200 mg/day groups (85 and 87, respectively) were followed over the next 1–2 years (mean 20 months), off trial medication.

Results

In the core trial, BMD increased at all sites by 1.0–1.5 % at 2 years in the group receiving calcium 1,200 mg/day, compared to the group receiving placebo. In post-trial follow-up, the calcium group has some residual benefit at the total body (0.41 % above placebo; P = 0.04) but there was no significant between-group differences at other sites.

Conclusion

Following cessation of calcium supplements in healthy men, there is a small residual benefit in total body BMD, but not at the hip or spine. This is unlikely to confer a clinically significant dividend in terms of ongoing fracture prevention.