Background/Objectives: The relationship between dairy consumption and cardiovascular or bone health outcomes remains controversial, with inconsistent findings across existing meta-analyses. In this study, we aimed to systematically evaluate and synthesize the evidence from published meta-analyses on dairy consumption and cardiovascular and bone health outcomes in adults, and to conduct updated meta-analyses incorporating recently published prospective cohort studies. Methods: We performed an umbrella review following PRISMA guidelines, searching published and grey literature up to April 2024. Meta-analyses evaluating dairy intake and its impact on cardiovascular and bone health outcomes were included. Updated meta-analyses were conducted for cardiovascular outcomes, while bone health outcomes were synthesized qualitatively. Methodological quality was assessed using the Joanna Briggs Institute checklist. Random-effects models were applied, and heterogeneity, small-study effects, excess significance, and prediction intervals were evaluated. Results: We included 33 meta-analyses (26 on cardiovascular, 7 on bone health outcomes). Updated meta-analyses showed that total dairy (RR: 0.96), milk (RR: 0.97), and yogurt (RR: 0.92) were significantly associated with reduced CVD risk. Total dairy and low-fat dairy were inversely linked to hypertension (RRs: 0.89, 0.87), and milk and low-fat dairy were associated with reduced stroke risk. Small-study effects were absent for most associations. Credibility was rated as “weak” for most associations, with total dairy and stroke, and total dairy and hypertension showing "suggestive" evidence. For bone health, dairy—especially milk—was linked to higher bone mineral density (BMD). Evidence on osteoporosis risk was mixed, and while total dairy and milk showed inconsistent associations with fractures, cheese and yogurt showed more consistent protective effects. Limited evidence suggested milk may reduce bone resorption markers. Conclusions: This review suggests that dairy consumption, particularly milk and yogurt, is modestly associated with reduced cardiovascular risk, while dairy intake appears to benefit BMD and fracture prevention. However, further research is needed to confirm these associations.

We aimed to evaluate the impact of calcium supplementation on bone mineral density (BMD), osteoporosis, and site-specific fracture risk in adults. We conducted a systematic search of MEDLINE, EMBASE, Web of Science, the Cochrane Database of Systematic Reviews (CDSR), and CINAHL from inception to February 13, 2025, to identify systematic reviews with meta-analyses assessing calcium supplementation and fracture or osteoporosis outcomes in adults (≥18 years). Primary-study data from eligible meta-analyses were extracted to assess pooled estimates. Certainty of evidence was assessed using the GRADE framework. Twenty-two meta-analyses were included, comprising 69 unique primary studies and 286,584 participants. Calcium supplementation, with or without vitamin D, was associated with small but statistically significant increases in BMD at the total body, hip, lumbar spine, and femoral neck, although heterogeneity was substantial. Calcium supplementation was associated with reduced risk of total, vertebral, and non-vertebral fractures, but not hip or wrist fractures. Subgroup analyses by intervention type, sex, and age showed no consistent differential effects. Certainty of evidence ranged from moderate for vertebral and non-vertebral fractures to low or very low for other outcomes. Overall, calcium supplementation confers modest skeletal benefits. Further high-quality long-term trials are still needed. (PROSPERO Registration Number: CRD420251082510)