Association between calcium supplementation and bone mineral density in children: a systematic review and meta-analysis

Abstract Objective To evaluate the effects of calcium supplementation on bone mineral density in children. Methods The PubMed, Embase, and Cochrane library were systematically searched. The retrieve inception date was between October 2001 and October 2019. Two reviewers independently performed the data extraction and assessed methodology quality. Studies were limited to randomized clinical trials comparing calcium supplement with a placebo for bone mineral density in children. A meta-analysis was performed to calculate standard mean difference (SMD) and 95% confidence interval (CI). Results A total of 6 randomized controlled trials involving 408 participants (calcium supplementation group: 198; placebo group: 210) were finally included in this study. The meta-analysis revealed that, compared with placebos, calcium supplementation had no effect on the bone mineral densities [the whole-body: SMD with CI = 0.43 (−0.05–0.91), P=0.08, I2 = 75%; the 2nd–4th lumbar vertebrae: SMD with 95% CI = 0.27 (−0.17 to 0.70), P = 0.07, I2 = 0%)]. Sensitivity analysis revealed that the results of the whole-body bone mineral density were unstable and that the bone density of the 2nd–4th lumbar spine was robust. Conclusions The results of this meta-analysis suggested that calcium supplementation did not improve bone mineral density in children. However, there continues to be a need for more high-quality studies to verify this fact in the future.