Effect of calcium and vitamin D co-supplementation on lipid profile of overweight/obese subjects: a systematic review and meta-analysis of the randomized clinical trials

Abstract Background Results of the studies assessed the effect of calcium and vitamin D co-supplementation on lipid profiles are contradictory. Due to the inconsistent results found in the literature, we performed a systematic review and meta-analysis of randomized clinical trials (RCTs) to assess the effect of calcium and vitamin D co-supplementation on lipids concentrations. Methods A systematic search was carried out in Web of Science, PubMed, Scopus and Cochrane library without any language and time restriction up to March, 2019, to retrieve the randomized controlled trials (RCTs) which examined the effect of calcium and vitamin D co-supplementation on lipids concentrations in overweight/obese subjects. Meta-analyses were carried out using a random effects model. I2 index was used to evaluate the heterogeneity. Results Initial search yielded 1847 publications. Seven RCTs with 414 patients were eligible. Results show that lower doses of vitamin D and calcium significantly reduced TG and TC levels. Furthermore, we found that this co-supplementation increased the blood concentrations of HDL-C. The effect of calcium and vitamin D co-supplementation on increasing HDL-C was significant in equal or less than 8 weeks supplementation and in higher doses of vitamin D and calcium. In addition, we found that this co-supplementation significantly reduced LDL-C in equal or less than 8 weeks supplementation. Conclusion Present systematic review and meta-analysis indicated the beneficial effects of calcium and vitamin D co-supplementation on lipid profile of overweight/obese subjects. We found that the lower doses and short-term supplementation could have more beneficial effects.