The Effects of Dietary Calcium Supplements Alone or With Vitamin D on Cholesterol Metabolism A Meta-Analysis of Randomized Controlled Trials

Background: Evidence supports the role of lifestyle interventions as a primary intervention strategy among individuals with dyslipidemia. The role of micronutrients, and calcium in particular, on cholesterol metabolism is not clear and warrants further investigation. Objective: The aim of this study is to conduct a meta-analysis of controlled clinical trials that have examined the effects of calcium supplements on blood lipids among adults. Methods: MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials databases were searched up to March 2016 for calcium supplements clinical trials. Other trials were selected from searching bibliography of reviews, meta-analysis, and included trials. Clinical trials with random allocation to calcium supplementation or calcium plus vitamin D supplementation, or control were selected. Data collected included study design, participant characteristics, information of the intervention, and outcomes. Data synthesis was conducted using random effect models. Results: A total of 22 trials, representing 4071 participants, met the eligibility criteria. Compared with control group, calcium supplements significantly reduced low-density lipoprotein cholesterol level by -0.12 mmol/L (95% confidence interval, -0.22 to -0.02) and increased high-density lipoprotein cholesterol level by 0.05 mmol/L (95% confidence interval, 0.00 to 0.10). Subgroup analyses revealed that the associations were consistent across study duration and vitamin D cosupplementation status. Conclusions: Calcium supplementation has beneficial effect on blood lipids. Such supplements may be useful as a nonpharmaceutical strategy in cholesterol control.