The results of an analysis from the Nurses' Health Study reported that higher zinc intake may be associated with a slightly lower risk for type 2 diabetes in women. The aim of this analysis was to determine the interaction of zinc intake with risk for type 2 diabetes in US women. The study cohort consisted of 82,297 women who were aged 33 to 60 years at baseline in 1980 and who were followed up to 2004 in the Nurses' Health Study. From 1980 to 2002, a validated food frequency questionnaire (FFQ) was administered to measure dietary intakes of zinc and other nutrients. There were 6030 incident cases of type 2 diabetes during 24 years of follow-up. Comparing the highest with the lowest quintiles of intake, the relative risks (RRs) of type 2 diabetes were 0.90 (95% confidence interval [CI] 0.82 - 0.99; P trend = .04) for total zinc and 0.92 (95% CI, 0.84 -1.00; P trend = .009) for dietary zinc from food sources, after adjustment of lifestyle and dietary risk factors. There was also an inverse association between type 2 diabetes and dietary zinc–to–heme iron ratio. RRs across quintiles of this ratio, after multivariate adjustment of covariates, were 1.0 (reference), 0.93 (95% CI, 0.86 - 1.01), 0.86 (95% CI, 0.79 - 0.94), 0.82 (95% CI, 0.75 - 0.90), and 0.72 (95% CI, 0.66 - 0.80), respectively (P trend < .0001). Limitations of this study include possible residual confounding; some measurement error in assessment of zinc intake; possible lack of generalizability to nonwhite women or to those of other professions; and significant associations observed only after using cumulative average of diet and stopping diet updates after participants developed chronic diseases.