A review of calcium supplements and cardiovascular disease risk

Area of Science:

• Nutrition Science
• Cardiovascular Epidemiology
• Bone Health Research

Background:

• Concerns exist regarding potential cardiovascular risks associated with calcium supplement use.
• Some studies suggest a possible association between calcium supplements and adverse cardiovascular events.
• Existing research has limitations, including compliance issues and potential bias, questioning reported associations.

Purpose of the Study:

• To critically evaluate the evidence linking calcium supplement intake to cardiovascular event risk.
• To assess the strength, consistency, dose-response, and biological plausibility of the hypothesized relationship.
• To determine if current evidence warrants a change in recommendations for calcium supplementation.

Main Methods:

• Review of epidemiological studies and meta-analyses of randomized controlled trials.
• Examination of subgroup analyses, including data from the Women's Health Initiative.
• Application of Bradford Hill criteria for causal inference to assess the calcium-cardiovascular link.

Main Results:

• Methodological limitations in studies reporting adverse cardiovascular events (e.g., bias, confounding) were identified.
• Other cohort studies indicate no detrimental cardiovascular effects from dietary or supplemental calcium, with or without vitamin D.
• Limited evidence supports plausible biological mechanisms connecting calcium supplements to adverse cardiovascular outcomes.

Conclusions:

• The current evidence is insufficient to establish a causal relationship between calcium supplement use and increased cardiovascular disease risk.
• Existing recommendations from the Institute of Medicine for calcium supplementation for bone health should be maintained.
• Further research may be needed, but current data do not support altering supplementation guidelines based on cardiovascular concerns.