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 and metabolism
Q1
Mar 2008
Citations:124
Influential Citations:3
Interventional (Human) Studies
93
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Methods
Five-year randomized, double-blind, controlled trial of 120 community-dwelling, ambulant women aged 70–80 years; not on bone-active therapy; conducted in sunny Western Australia.
Intervention
Oral supplementation for 5 years in three arms: calcium carbonate 1200 mg/day with placebo vitamin D; calcium carbonate 1200 mg/day with vitamin D2 1000 IU/day; placebo calcium with placebo vitamin D2.
Results
Hip BMD was preserved at 1 year in both calcium-alone and calcium+vitamin D groups (Ca −0.19%; CaD −0.17%) vs controls (−1.27%). By year 3 and 5, preservation persisted only in the calcium+vitamin D group. Benefits were greater in those with baseline 25OHD < 68 nmol/L. Year 1: alkaline phosphatase fell 6.8% in Ca and 11.3% in CaD; urinary DPD/Cr fell 28.7% (Ca) and 34.5% (CaD). At year 5, suppression of turnover persisted only in CaD. In participants with high baseline PTH, CaD reduced PTH by 27.8% at year 3 and 31.3% at year 5 vs controls. Intestinal calcium absorption did not differ among groups at high calcium loads. No differences in adverse events, cancer, vascular disease, or kidney stones were observed. Authors conclude that adding vitamin D to calcium yields long-term benefits on hip bone density in elderly women in sunny climates, likely via sustained reduction in bone turnover.
Limitations
No vitamin D–alone arm; no fracture outcomes reported; small per-group sample size (~40); single geographic setting (Perth, Western Australia) which may limit generalizability; intestinal calcium-absorption measures do not capture calcium losses to bone/urine; ergocalciferol (D2) used rather than cholecalciferol (D3).

Abstract

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 supplementatio...