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.
- vitamin A
- vitamin E