Objective. To assess nutrient intakes and vitamin levels in 79 patients with rheumatoid arthritis participating in a trial and to determine whether changes in body mass index were associated with changes in disease activity. Methods. This study evaluated baseline vitamin levels, 1-day dietary intakes, and weight every 3 months for 1 year. Linear regression analysis was used to evaluate the relationship of time to body mass index. Analysis of covariance wets used to determine if body mass index, time, or treatment had an effect on disease activity. Results. Deficient vitamin levels and poor nutrient intake patterns were prevalent in the study population. Changes in body mass index over time did nor correlate with changes in disease activity. Conclusions. Rheumatoid arthritis patients are at high risk of obesity, abnormal vitamin levels, and poor nutrient intakes. Changes in body mass index failed to correlate with changes in disease activity.