FIGURE 10.

Dietary β-carotene and blood concentrations of β-carotene and cardiovascular disease: dose-response analyses. (A) Dietary β-carotene and cardiovascular disease: linear dose-response analysis. The summary RR per 5000 µg/d was 0.87 (95% CI: 0.63, 1.20, I² = 58%, P_{heterogeneity} = 0.10, n = 3). (B) β-Carotene in blood and cardiovascular disease: linear dose-response analysis. The summary RR per 25 µg/dL was 0.85 (95% CI: 0.76, 0.95, I² = 9%, P_{heterogeneity} = 0.36, n = 7). (C) Dietary β-carotene and cardiovascular disease: nonlinear dose-response analysis. There was no evidence of nonlinearity between dietary β-carotene and cardiovascular disease (P_nonlinearity = 0.51). (D) β-Carotene in blood and cardiovascular disease: nonlinear dose-response analysis. There was evidence of nonlinearity for β-carotene in blood and cardiovascular disease (P_nonlinearity = 0.006). Summary RRs and 95% CIs were calculated with the use of random-effects models, and the nonlinear dose-response analyses were conducted with the use of restricted cubic splines.