Objective: To assess relationships between energy, nutrient and food intakes, alcohol consumption, smoking status and body mass index (BMI), and serum concentrations of b-carotene, a-tocopherol, vitamin C, selenium and zinc. Methods: Data on health status, alcohol consumption, smoking habits, anthropometric data and biochemical measurements were obtained in 1821 women aged 35-60 y and 1307 men aged 45-60 y, participant to the SU.VI.MAX Study. Data on dietary intake were available on a subsample who reported six 24-h dietary records during the first 18 months of the study. Results: Women had higher baseline serum b-carotene and vitamin C concentrations and lower concentration for serum vitamin E, zinc and selenium than men. In women, younger age was associated with lowered mean concentration of serum b-carotene, vitamin E and selenium. In men, only differences were observed for serum zinc, which was lower in older men. Current smokers of both sexes had significantly lower concentrations of serum b-carotene, vitamin C and selenium, and, only in women, of vitamin E, than nonsmokers. Alcohol consumers had lower concentrations of serum b-carotene and higher selenium concentrations. Serum b-carotene and vitamin C concentrations were lower in obese subjects. There were positive associations of dietary b-carotene, vitamin C and E with their serum concentrations. Age, nutrient and alcohol intakes, serum cholesterol, BMI and smoking status explained 15.2% of the variance of serum b-carotene in men and 13.9% in women, and 10.8 and 10.0% for serum vitamin C, and 26.3 and 28.6% for serum vitamin E, respectively. Conclusion: Serum antioxidant nutrient concentrations are primarily influenced by sex, age, obesity, tobacco smoking, alcohol consumption and especially dietary intake of those antioxidant nutrients. IntroductionCigarette smoking, obesity and some dietary patterns are well-known risk factors for both cardiovascular disease and cancer (WCRF/AIC; Kromhout, 2001). Yet, in the past several years, an increasing number of basic and clinical studies have pointed to the role of the reactive metabolites of oxygen, the free radicals, in these pathological processes, and the potential protective effect of antioxidant nutrients such as bcarotene, vitamin C, vitamin E, selenium and zinc (Ames, Halliwell & Gutteridge, 1989;Diplock, 1991;Byers & Perry, 1992;Frei, 1994;Hercberg et al, 1998a).Epidemiological data from cross-sectional, case-control, and prospective studies have shown a strong relationship between the intake of foods rich in antioxidant vitamins and minerals, or the actual intake of these nutrients, and the risk of cancer and ischaemic cardiovascular diseases (CVD) (Block et al, 1992;Stampfer & Rimm, 1993;Byers & Guerrero, 1995;Kohlmeier & Hastings, 1995;Stampfer & Rimm, 1995;Hercberg et al, 1998a). However, most of published randomized placebo-controlled primary prevention trials have not been able to demonstrate these potential beneficial effects (Blot et al, 1993; The AlphaTocopherol, Beta Carotene Cancer Preventi...