Background & Aim: Micronutrients deficiency is one of the most common health problems among adolescents. Theory based educational interventions which address learners&apos preferences are among the solutions for the matter in hand. The aim of this study was to determine the effectiveness of the Transtheoretical model (TTM) based educational package on vitamin intake in female adolescents in Tehran.

Methods & Materials: A randomized community trial was applied. Study samples were consisted of 80 female students from two middle schools of Tehran, district 17^th. They were selected using a cluster-random sampling method and were randomly assigned to the intervention (n=40) and control groups (n=40). The intervention group received a TTM-based educational package. Changes in vitamin intake were assessed using standard food frequency & 24-recall questionnaires.

Results: Based on pre-test results, intake of vitamin B2, B6, B9, B12, and C were lower than Dietary Reference Intake (DRI) in both groups. Based on the post-test data, a significant increase occurred in the mean score of vitamin intake in the intervention group comparing with the control group and also with the intervention group at pretest (P<0.05).

Conclusion: TTM-based educational package could be effective in improving vitamin intake in urban female adolescents.

Background & Aim: This study aimed to assess relationship between perceived benefits/barriers and decisional balance with stages of change for physical activity among high school students in Bandar Abbas, Iran.

Methods & Materials: This cross-sectional study was conducted in high schools of Bandar Abbas, in the south of Iran. A total of 422 high school students were selected. Twenty two participants did not fill out questionnaires completely. A total of 400 questionnaires were analyzed (response rate=94.8%). The perceived benefits/ barriers to exercise and decisional balance were assessed using the Exercise Benefits/Barriers Scale and stages of change were assessed using the Physical Activity staging. Data were analyzed in the SPSS v.16.

Results: The mean age of the participants was 15.9 (SD=1.1) ranging from 14 to 18 years. More than half of the participants (51.8%) were male and 48.2% were female. About half of the participants (49.2%) were engaged in regular physical activities. Fifteen per cent of the participants in the precontemplation stage, 15.8% in the contemplation stage, 20% in preparation stage, 15.8% in action stage, and 33.4% in maintenance stage for physical activity. From precontemplation stage to maintenance stage, the perceived benefits and decisional balance were increased and the perceived barriers was decreased.

Conclusion: The results of this study are in line with the Transtheoretical model. This model can be used as a framework to design interventions for improving physical activity in population.