Associations of Dietary Calcium and Phosphorus With Vascular and Valvular Calcification: The ARIC Study

Background: High dietary calcium and phosphorus may accelerate vascular calcification, but epidemiological data are inconsistent. Most of those studies assessed diet at one point and have not been systematically evaluated. Objectives: The purpose of this study was to assess the associations of dietary calcium and phosphorus intakes in middle age with coronary artery and extra-coronary calcification at older age. Methods: We studied 1,914 participants from the Atherosclerosis Risk in Communities Study (mean age 80.5 years) without coronary heart disease who underwent chest computed tomography scans at visit 7 (2018-2019) and completed a 66-item food frequency questionnaire at two earlier visits (visit 1 [1987-1989] and visit 3 [1993-1995]). Dietary calcium and phosphorus intakes were averaged between these two visits. Calcification was quantified by the Agatston score in coronary artery, ascending aorta, descending aorta, aortic valve ring, aortic valve, and mitral valve. Results: Dietary calcium intake was inversely associated with coronary artery and ascending aorta calcification, whereas the association was not significant for other measures of extra-coronary calcification. For example, the highest vs lowest quartile of calcium intake showed an adjusted OR of 0.66 (95% CI: 0.45-0.98) for coronary artery calcification (Agatston score ≥75th percentile). Dietary phosphorus intake demonstrated similar results, but the magnitude of the association was weaker than dietary calcium intake. Conclusions: Dietary calcium and phosphorus intakes at middle age were not positively associated with vascular and valvular calcification at over 75 years old. Our findings did not support the link between a calcium or phosphorus-rich diet and vascular and valvular calcification.