A prospective study of calcium intake from diet and supplements and risk of ischemic heart disease among men

Background: Calcium intake is thought to have a protective effect on the risk of developing ischemic heart disease (IHD), but the existing data are inconsistent. Objective: The objective was to assess the relation between calcium intake and risk of IHD among men. Design: Men in the Health Professionals Follow-up Study who returned a dietary questionnaire in 1986 (n = 39 800) were followed up for 12 y. Intakes of calcium and other nutrients were assessed in 1986, 1990, and 1994. The endpoints of total IHD (nonfatal myocardial infarction and fatal IHD) incidence were ascertained by medical record review. Other IHD risk factors were recorded biennially. Results: During 12 y of follow-up (415 965 person-years), we documented 1458 cases of IHD: 1030 of nonfatal myocardial infarction and 428 of fatal IHD. After control for standard IHD risk factors, the relative risk of developing IHD among men in the highest (median intake = 1377 mg/d) compared with the lowest (median intake = 523 mg/d) calcium intake quintile was 0.97 (95% CI: 0.81, 1.16; P for trend = 0.64), for vitamin D intake was 1.00 (95% CI: 0.80, 1.24; P for trend = 0.66), and for total dairy product intake was 1.01 (95% CI: 0.83, 1.23; P for trend = 0.57). For supplemental calcium intake, the relative risk of developing IHD in a comparison of the highest quintile with nonusers of supplements was 0.87 (95% CI: 0.64, 1.19; P for trend = 0.31). Conclusion: The results suggest that neither dietary nor supplemental intakes of calcium are appreciably associated with the risk of IHD among men.