High intakes of dietary calcium, dairy products may protect against MetS

Adults who have high dietary calcium and dairy product intakes are less likely to develop metabolic syndrome (MetS), suggests a meta-analysis.

A team of investigators searched the databases of PubMed, Cochrane Library, ClinicalTrials.gov, and Scopus for eligible cross-sectional studies assessing dietary calcium or dairy intake and MetS until October 2025 following the PRISMA 2020 guidelines. Longitudinal studies, non-English articles, and paediatric populations were excluded from the analysis.

An adapted Newcastle‒Ottawa scale was used to assess quality. The investigators then performed random-effects meta-analyses to pool fully adjusted odds ratios (ORs) and 95 percent confidence intervals (CIs) comparing the highest with the lowest intake categories.

Twenty-four studies (12 for dietary calcium intake and 12 for dairy products) met the eligibility criteria.

Higher intake of dietary calcium resulted in a 15-percent lower MetS probability (pooled OR, 0.85, 95 percent CI, 0.80‒0.91) despite substantial heterogeneity (I²=70.1 percent). Likewise, higher dairy intake inversely correlated with MetS (pooled OR, 0.78, 95 percent CI, 0.72‒0.85; I²=64.6 percent). Trim-and-fill analysis validated the strength of these findings, but small-study effects were noted for dairy.

In addition, higher calcium intake led to favourable profiles in individual MetS components, such as blood pressure, high-density lipoprotein cholesterol, waist circumference, triglycerides, and fasting glucose.

“However, the cross-sectional nature of the included studies precludes any inference of causality between calcium intake and MetS,” the investigators said. “Therefore, although these findings suggest a protective role of calcium-rich diets, well-designed prospective and interventional studies are warranted to clarify whether this relationship is causal.”