Table 2.
Prospective Cohorts Examining the Effects of Calcium With or Without Vitamin D Supplementation on CVD Outcomes
| Name of First Author, Publication Year | Sample Size | Intervention | Primary CVD Outcome | Follow‐Up Duration, y | Relevant Findings |
|---|---|---|---|---|---|
| Adebamowo, 201532 | 42 669 | Dietary and supplemental calcium | Incidence of stroke | 24 | No significant effect of dietary (HR, 0.85; CI, 0.73–1.00 [P=.1]) or supplemental (HR, 0.94; CI, 0.80–1.10 [P=.43]) calcium on the incidence of stroke |
| Adebamowo, 201532 | 180 864:86 149 in Nurses’ Health Study and 94 715 in Nurses’ Health Study II | Dietary and supplemental calcium | Incidence of stroke | 30 |
A protective effect of dietary calcium on incidence of stroke (HR, 0.85; 95% CI, 0.76–0.94 [P=.006]) No significant effect of dietary or supplemental calcium on incidence of stroke (HR, 0.97; 95% CI, 0.87–1.09) |
| Khan, 201533 | 41 514 | Dietary calcium | Incidence of nonfatal CVD, incidence of stroke events | 12 | Significant protection against nonfatal CVD (HR, 0.84; 95% CI, 0.70–0.99 [P=.04]) and stroke (HR, 0.69; 95% CI, 0.51–0.93 [P=.02]) |
| Larsson, 201134 | 34 670 | Supplemental calcium | Incidence of stroke | 10.4 | Increased risk of stroke with calcium supplementation (RR, 2.04; 95% CI, 1.24–3.35 [P=.47]) |
| Block, 200535 | 129 | Supplemental calcium | Effect on CACS | 1.5 | Progressive increase in patients with CACS >30 (P<.05) |
| Al‐Delaimy, 200336 | 39 800 | Dietary and supplemental calcium and vitamin D | Incidence of IHD | 12 | No association was found between dietary (RR, 0.93; 95% CI, 0.77–1.14 [P=.27]) and supplemental (RR, 0.87; 95% CI, 0.64–1.19 [P=.31]) calcium and vitamin D |
| Ascherio, 199837 | 43 738 | Supplemental calcium | Incidence of stroke | 8 | Nonsignificant decrease in the risk of stroke (RR, 0.88; 95% CI, 0.63–1.23 [P=.1]) |
| Chan, 201338 | 3139 | Dietary calcium | Death from CVD | 9.1 | Nonsignificant decrease in the risk of death from CVD (HR, 0.70; 95% CI, 0.41–1.21 [P=.228]) |
| Iso, 199939 | 85 764 | Calcium supplementation | Incidence of stroke | 1 164 674 person‐years | Protective effect of supplemental calcium (RR, 0.69; 95% CI, 0.50–0.95 [P=.02]) |
| Kaluza, 201040 | 23 366 | Dietary calcium intake | CVD mortality | 10 | No association between dietary calcium and CVD mortality (HR, 0.91; 95% CI, 0.75–1.10 [P=.77]) |
| Larsson, 200841 | 26 556 | Dietary calcium intake | Incidence of stroke | 13.6 | No effect on incidence of stroke (RR, 0.96; 95% CI, 0.84–1.10) |
| Li, 201242 | 23 980 | Dietary calcium intake | CVD deaths, incidence of MI, and stroke | 11 | Nonsignificant decrease in risk of MI (RR, 0.67; 95% CI, 0.48–0.94 [P=.39]) and a neutral association with the risk of stroke (RR, 1.17; 95% CI, 0.77–1.77) and CVD mortality (RR, 1.22; 95% CI, 0.83–1.81) |
| Michaelsson, 201343 | 61 433 | Dietary and supplemental calcium | Incidence of MI, stroke, and CVD mortality | 11 |
Dietary calcium intake was associated with increased risk of CVD‐related death (HR, 1.49; 95% CI, 1.09–2.02) and IHD (HR, 2.14; 95% CI, 1.48–3.09) but no association with risk of stroke (HR, 0.73; 95% CI, 0.33–1.65) Total calcium intake was associated with increased risk of CVD mortality (RR, 1.51; 95% CI, 1.23–1.84) and IHD (HR, 1.90; 95% CI, 1.45–2.49) but not stroke (HR, 0.96; 95% CI, 0.61–1.50) |
| Paik, 201444 | 74 245 | Dietary and supplemental calcium and vitamin D | Incidence of CHD and stroke | 24 | Protective effect against the risk of CHD (RR, 0.71; 95% CI, 0.61–0.83 [P< .001]) but neutral effect against the risk of stroke (RR, 1.03; 95% CI, 0.87–1.21 [P= .61]) |
| Sluijs, 201445 | 36 094 | Dietary and supplemental calcium | Incidence of stroke | 12 | Neutral effect of dietary (RR, 0.90; 95% CI, 0.68–1.19) supplemental (RR, 0.98; 95% CI, 0.75–1.29) calcium on stroke |
| Umesawa, 200846 | 41 526 | Dietary calcium | Incidence of CHD and stroke | 533 692 person‐years | Protective effect against the risk of stroke (HR, 0.70; 95% CI, 0.56–0.88 [P=.007]) but neutral effect against CHD (HR, 0.94; 95% CI, 0.59–1.51 [P=.17]) |
| Weng, 200847 | 1772 | Dietary calcium | Incidence of ischemic stroke | 10.6 | Increased risk of ischemic stroke (RR, 1.66; 95% CI, 1.08–2.53 [P=.017]) |
| Yang, 201619 | 132 823 | Dietary and supplemental calcium | All‐cause mortality and CVD‐specific death | 17.5 |
For men: nonsignificant increased risk of all‐cause mortality with supplemental calcium (RR, 1.17; 95% CI, 1.03–1.33), specifically CVD‐specific mortality (RR, 1.22; 95% CI, 0.99–1.51) For women: protective effect against all‐cause mortality (RR, 0.93; 95% CI, 0.87–0.99 [P<.01]) Dietary calcium was not associated with all‐cause mortality in both sexes |
| Xiao, 20131 | 388 229 | Dietary and supplemental calcium intake | All CVD death |
Increased risk of CVD mortality with supplemental calcium in men (RR, 1.20; 95% CI, 1.05–1.36), specifically death from cardiac disease (RR, 1.19; 95% CI, 1.03–1.37) No associated mortality or benefit found in women taking supplemental calcium (RR, 1.06; 95% CI, 0.96–1.18) Dietary calcium intake was unrelated to CVD death in men (RR, 1.04; 95% CI, 0.97–1.12) and women (RR, 1.04; 95% CI, 0.94–1.15) |
Abbreviations: CACS, coronary artery calcification score; CHD, coronary heart disease; CI, confidence interval; CVD, cardiovascular disease; HR, hazard ratio; IHD, ischemic heart disease; MI, myocardial infarction; RR, relative risk.