The study was based on analysis of the UK Biobank, a very large study comprising 502,664 men and women aged 40-69 years.
Of the total UK Biobank participants, 34,890 individuals (6.94%) reported taking calcium supplements, 20,004 taking vitamin D supplements, and 10,406 taking both (2.1%). The researchers found no associations between the use of calcium supplements and hospital admissions related to ischaemic heart disease (e.g. heart attacks), any cardiovascular event, or death following admission for either admission category. Results were similar for vitamin D and combination supplementation.
Furthemore, regardless of whether participants had a history of cardiovascular disease or not at baseline, calcium supplementation (with or without vitamin D) did not increase the risk of future cardiac events, findings which remained robust after other factors such as age, fatness, medication use and blood pressure were considered.
Presenting author Prof. Nicholas C. Harvey of the MRC Lifecourse Epidemiology Unit, University of Southampton, noted, "Calcium supplementation is widely used, including as an adjunct to therapy for osteoporosis. Previous studies have provided inconsistent findings with regard to associations between calcium supplements and cardiovascular events. Our results, using the largest single study to date, provide reassurance that such supplementation appears safe."