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

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 supplements of 500 or 250 mg/d effectively prevent bone loss in perimenopausal and postmenopausal Japanese women. We recruited 450 Japanese women between 50 and 75 years of age. They were randomly assigned to receive 500 mg of calcium (as calcium carbonate), 250 mg of calcium, or placebo daily. Medical examinations conducted three times over a 2-year follow-up period assessed bone mineral density (BMD) of the lumbar spine and femoral neck. One-factor repeated measures ANOVA was used for statistical tests. Subgroup analyses were also conducted. Average total daily calcium intake at baseline for the 418 subjects who underwent follow-up examinations was 493 mg/d. Intention-to-treat analysis showed less dramatic decreases in spinal BMD for the 500-mg/d calcium supplement group compared to the placebo group (1.2% difference over 2 years, p ¼ 0.027). Per-protocol analysis (!80% compliance) revealed that spinal BMD for the 500-mg/d and 250-mg/d calcium supplement groups decreased less than the placebo group (1.6%, p ¼ 0.010 and 1.0%, p ¼ 0.078, respectively), and that femoral neck BMD for the 500-mg/d calcium supplement group decreased less relative to the placebo group (1.0%, p ¼ 0.077). A low-dose calcium supplement of 500 mg/d can effectively slow lumbar spine bone loss in perimenopausal and postmenopausal women with habitually low calcium intake, but its effect on the femoral neck is less certain. Calcium supplementation dosage should thus be reassessed. (Clinical Trials Registry number: UMIN000001176). ß

Changes in vascular calcification and bone mineral density in calcium supplement users from the Canadian Multi-center Osteoporosis Study (CaMOS)

“…Both calcium supplement users and non-users lost BMD at all three sites, suggesting that calcium supplementation at this dose may not have a protective effect on BMD. This is consistent with a 2012 study that found a calcium supplement dose below 500 mg/day did not offer any BMD protection to femoral neck or total hip sites in older women [40]. It has been proposed that low-dose calcium supplements are most effective at preventing BMD loss in women with low dietary calcium intake (< 400 mg/day) [41].…”

Calcium, Is It Better to Have Less?—Global Health Perspectives

“…Supplementation of as low as 500 mg of calcium could effectively slow lumbar spine bone loss in Japanese perimenopausal women with low calcium intake [Nakamura et al, ]. Similar beneficial effects have been observed in postmenopausal women from Hong Kong [Lau et al, ; Haines et al, ; Lee et al, ; Lau et al, ; Ho et al, ], China [Gui et al, ], Chile [Rodriguez and Novik, ], Argentina [Malpeli et al, ] and Nigeria [Umaretiya et al, ].…”

Personalising nutrition for older adults: The InCluSilver project

“…In the second study, 450 perimenopausal women (up to the age of 75 years) were randomly assigned to receive 500 mg or 250 mg of calcium (as calcium carbonate), or placebo daily (mean baseline calcium intake of 493 mg/day) (Nakamura et al . ). The higher dose was effective at reducing bone loss in the pre‐menopausal women who had low baseline intake of calcium.…”