Myocardial infarction was more commonly reported in the calcium group than in the placebo group (45 events in 31 women v 19 events in 14 women, P=0.01). The composite end point of myocardial infarction, stroke, or sudden death was also more common in the calcium group (101 events in 69 women v 54 events in 42 women, P=0.008). After adjudication myocardial infarction remained more common in the calcium group (24 events in 21 women v 10 events in 10 women, relative risk 2.12, 95% confidence interval 1.01 to 4.47). For the composite end point 61 events were verified in 51 women in the calcium group and 36 events in 35 women in the placebo group (relative risk 1.47, 0.97 to 2.23). When unreported events were added from the national database of hospital admissions in New Zealand the relative risk of myocardial infarction was 1.49 (0.86 to 2.57) and that of the composite end point was 1.21 (0.84 to 1.74). The respective rate ratios were 1.67 (95% confidence intervals 0.98 to 2.87) and 1.43 (1.01 to 2.04); event rates: placebo 16.3/1000 person years, calcium 23.3/1000 person years. For stroke (including unreported events) the relative risk was 1.37 (0.83 to 2.28) and the rate ratio was 1.45 (0.88 to 2.49).
Calcium supplementation in healthy postmenopausal women is associated with upward trends in cardiovascular event rates. This potentially detrimental effect should be balanced against the likely benefits of calcium on bone. Citation: BMJ. 2008 February 2; 336(7638): 262–266. Published online 2008 January 15. IT IS LIKELY THAT CALCIUM SUPPLEMENTATION SHOULD BE CLOSELY MONITORED AND SERIOUS CONSIDERATION SHOULD BE MADE TO KEEP SUPPLEMENTATION AND FOOD SOURCED CALCIUM TO LESS THAN A TOTAL OF 1700 MG. A DAY. ADDITIONALLY CAUTION SHOULD BE USED IN RECOMMENDING CALCIUM SUPPLEMENTATION WITH PHOSPHORUS AS THERE ARE REPORTED INCREASES IN STONE FORMATION. EDWARD M. CONDON MD ECNU JAN 2013