BACKGROUND: Vitamin nutritional status may influence some xenobiotic metabolism or vice versa. METHODS: This analysis examines the relationship between B-vitamin concentrations and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDT) isomers and metabolites in healthy women. Serum pp'DDT, pp'DDE, pp'DDD, op'DDT, op'DDE, and serum folate, cysteine, and vitamins B6 and B12 were measured in 296 nonsmoking female textile workers (21-34 yr) in Anhui, China. Mean (SD) age and body mass index of this cohort were 24.9 (1.5) y and 19.7 (2.0) kg/m(2), respectively. RESULTS: Median pp'DDT, pp'DDE, pp'DDD, op'DDT, and op'DDE were 1.5, 29.2, 0.22, 0.17, and 0.09 ng/g, respectively. Median folate and cysteine were 9.2 and 200.0 nmol/L, respectively. Folate was significantly inversely associated with pp'DDT and pp'DDE: beta (95% confidence interval [CI]) = -0.23 (-0.39, -0.07) and -0.20 (-0.36, -0.05), respectively, and it was marginally associated with pp'DDD. Cysteine was significantly inversely associated with pp'DDT, beta (95% CI) = -0.69 (-1.00, -0.37); pp'DDE, beta (95% CI) = -0.32 (-0.62, -0.02); pp'DDD, beta (95% CI) = -0.31 (-0.59, -0.03); and op'DDT, beta (95% CI) = -0.35 (-0.68, -0.02). CONCLUSIONS: Folate and cysteine are independently inversely associated with DDT isomers, adjusting for vitamins B6 and B12, age, and body mass index. These nutrients may play a role in DDT metabolism; however, it is also possible that DDT may exert a negative impact on folate and cysteine levels. Longitudinal studies are needed to ascertain the direction of this association.