Correlations of vitamin A and E intakes with the plasma concentrations of carotenoids and tocopherols among American men and women

The authors investigated the association of diet and other factors with the plasma concentrations of carotenoids, retinol and tocopherols in a sample of 121 men and 186 women participating in two prospective investigations of dietary etiologies of chronic diseases. Lycopene (mean concentration, 0.82 μmol/L in men, 0.76 μmol/L in women), β-carotene (mean 0.46 μmol/L in men, 0.58 μmol/L in women) and lutein (mean 0.28 μmol/L in men, 0.27 μmol/L in women) were the major circulating carotenoids. Among nonsmokers, dietary carotenoid, as typically calculated in epidemiologic studies, was significantly correlated with plasma β-carotene (r = 0.34 in men, r = 0.30 in women), α-carotene (r = 0.52 in men, r = 0.37 in women) and lutein (r = 0.36 in men, r = 0.19 in women), but not with plasma zeaxanthin (r = 0.11 and r = 0.02) or lycopene (r = 0.13 and r = 0.01) after adjusting for plasma cholesterol and triglycerides, body mass index and energy intake. Total vitamin E intake was positively associated with plasma concentrations of α- tocopherol (r = 0.51 in men, r = 0.41 in women) and inversely associated with plasma concentrations of γ-tocopherol (r = -0.51 in men r = -0.42 in women), but this was primarily due to use of vitamin E supplements. Measurements of specific carotenoids can provide independent information beyond the usual calculation of carotene intake in epidemiologic studies.