Calcium supplements do not prevent fracturesBMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h4825 (Published 29 September 2015) Cite this as: BMJ 2015;351:h4825
- Karl Michaëlsson, professor
- 1Department of Surgical Sciences, Uppsala University, 751 85 Uppsala, Sweden
Calcium is vital to many biological processes, and serum concentration is tightly regulated. Net calcium excretion must be replaced, but the amount of calcium needed has been debated for decades. Twenty five years ago in this journal, Kanis and Passmore concluded that calcium supplements to prevent fractures were not justified by the available evidence,1 though this view was challenged by determined opponents. According to two linked articles,2 3 the conclusions of Kanis and Passmore still hold true. Furthermore, there seems little to be gained from an increased consumption of calcium rich foods.
In the first paper, Tai and colleagues (doi:10.1136/bmj.h4183) report a systematic review and meta-analysis of randomised controlled trials of extra dietary or supplemental calcium in women and men aged over 50.2 They found a meagre increase in bone mineral density, with no further gains beyond the first year. Importantly, this limited improvement was no greater when calcium was combined with vitamin D at any dose, even among participants with low serum concentration of 25-hydroxyvitamin D (25-OH-D), a high calcium dose, or baseline dietary calcium intake <800 mg/day.
In the second paper, Bolland and colleagues (doi:10.1136/bmj.h4580) explored whether increased calcium intake could reduce the …