Dietary calcium intake in relation to blood lipids and lipoproteins profiles: A systematic review and meta-analysis of epidemiologic studies

Aims: Findings of prior investigations on the association between calcium intake and lipid profiles were inconsistent. We performed a systematic review and meta-analysis on epidemiologic studies to evaluate the relationship of dietary calcium intake with blood lipids and lipoproteins. Data synthesis: A systematic search up to April 2021 was performed in different electronic data -bases, including MEDLINE (PubMed), Scopus, Web of Science (ISI), and Google Scholar for epidemiological studies that considered dietary calcium intake as the exposure and reported risk of dyslipidemia or blood lipids and lipoproteins concentrations (as mean f SD or mean + SE or median (Inter Quartile Range) as the outcomes of interest in adult populations from both genders (18 years or older), regardless of their health status. Nineteen cross-sectional studies were included in the analysis. Combining estimates from 11 studies (including 33,304 subjects) revealed that individuals in the highest category of calcium intake, compared to the lowest one, had 5.94 mg/dL lower circulating triglyceride (TG) concentration (weighted mean difference (WMD):-5.94; 95% CI:-8.27,-3.62), 4.02 mg/dL lower circulating low-density lipoprotein cholesterol (LDL-c) levels (WMD:-4.02; 95% CI:-7.08,-0.95), and 1.56 mg/dL higher blood high-density lipoprotein cholesterol (HDL-c) (WMD: 1.56; 95% CI: 0.81, 2.30). Although meta-analysis on 13 studies (including 38,714 participants) did not reveal a significant relationship be-tween dietary calcium intake and odds of dyslipidemia or hyperlipidemia in the whole population, the highest vs. lowest level of calcium intake was related to 42% decreased odds of low blood HDL-c levels in females (95% CI: 0.40, 0.84) and 41% increased odds in males (95% CI: 1.21, 1.65). Conclusions: This meta-analysis demonstrated that individuals with the highest dietary calcium intake might have lower blood TG, LDL-c, and higher HDL-c concentrations as compared to those with the lowest calcium intake. However, the linkage between dietary calcium intake with odds of hyperlipidemia or dyslipidemia was not significant. Because of the cross-sectional nature of included studies, causality could not be proven. Further prospective studies are needed to affirm these findings.(C) 2022 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.