To describe changes in calcium and dairy intake during the transition from middle adolescence to young adulthood and to identify baseline correlates of calcium intake in young adulthood.Population-based, 5-year follow-up study (Project EAT: Eating Among Teens).Baseline surveys were completed in Minneapolis/St. Paul, MN schools and by mail at follow-up.Males and females (N = 1521) attending high school at baseline (mean age = 15.9 years) and with a mean age of 20.5 years at follow-up.Calcium intake.Mixed and linear regression methods were used to respectively examine trends and correlates of intake.During the transition to young adulthood, mean daily calcium intakes of females and males decreased by an average of 153 mg and 194 mg respectively. Mealtime milk availability, health/nutrition attitudes, taste preference for milk, healthful weight control behaviors, and peer support for healthful eating at baseline were associated with better follow-up calcium intake. Time spent watching television and lactose intolerance were associated with lower intake at follow-up.Nutrition interventions are needed to counter longitudinal decreases in calcium intake. Interventions targeted to adolescents should address the availability of milk at meals and other identified supports for healthful eating.