Effect of low‐dose calcium supplements on bone loss in perimenopausal and postmenopausal Asian women: A randomized controlled trial

Journal of Bone and Mineral Research
Q1
Nov 2012
Citations:30
Influential Citations:1
Interventional (Human) Studies
81
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Enhanced Details

Methods
Randomized, double-blind, placebo-controlled trial over 2 years; 450 healthy Japanese women aged 50–75 years, perimenopausal and postmenopausal; 418 completed follow-up.
Intervention
Calcium carbonate tablets: 500 mg/day (five tablets of 100 mg elemental Ca) or 250 mg/day (five tablets of 50 mg elemental Ca), or placebo; taken daily with meals; duration 2 years.
Results
Intention-to-treat: 500 mg/d calcium carbonate slowed lumbar spine bone loss over 2 years vs placebo (1.2 percentage-point difference; 3.0% vs 4.2% decline; p=0.027). The 250 mg/d dose showed no significant ITT difference. Per-protocol (≥80% compliance): 500 mg/d and 250 mg/d reduced spinal BMD loss by 1.6% (p=0.010) and 1.0% (p=0.078), respectively; femoral neck BMD showed no significant ITT differences (p=0.156 for 500 mg/d; p=0.565 for 250 mg/d). Per-protocol, hip BMD differences were small and not statistically significant. Serum calcium rose and intact PTH fell more with both calcium regimens; osteocalcin and NTX changes did not differ significantly. Subgroup analyses suggested stronger spinal BMD effects in participants with higher baseline calcium intake or adequate 25(OH)D status. Authors conclude that 500 mg/d calcium carbonate can effectively slow lumbar spine bone loss in perimenopausal/postmenopausal Japanese women with low calcium intake; effect on the femoral neck is uncertain; dosage optimization warrants further study.
Limitations
Two-year duration limits assessment of long-term fracture risk; no fracture outcomes reported; generalizability limited to Japanese women with low calcium intake; subgroup analyses were underpowered; 32 of 450 participants did not complete follow-up; adherence varied.

Abstract

Current standard‐dose calcium supplements (eg, 1000 mg/d) may increase the risk for cardiovascular events. Effectiveness of lower‐dose supplements in preventing bone loss should thus be considered. This study aimed to assess whether calcium supplemen...