Ten million people in the US have osteoporosis and 18 million people are at high risk for developing osteoporosis.Post-menopausal women are particularly vulnerable because they lose up to 15% of their bone mass during menopause and 1-2% a year for life. Loss of bone density may be prevented or delayed by engaging in specific health behaviors, including increases in calcium and vitamin D. The long-term objective of this applicant's program of research is to test the efficacy of patient-centered interventions to promote changes in health behaviors that lead to improvement in health outcomes. The purpose of this pilot study is to test the efficacy of a Tailored Interactive Computerized Intervention (TICI) to increase women's intake of calcium and vitamin D to prevent osteoporosis. Based on a theory of health behavior change, the Specific Aims of this pilot are to: (a) Determine differences in calcium and vitamin D intake between a treatment group receiving a TICI and a comparison group receiving usual care and education; (b) Describe women's use of and satisfaction with a computerized intervention; (c) Explore whether or not the effects of TICI are mediated through knowledge, outcome expectancy, self efficacy, perceived risk, or goal congruency and, (d) provide estimates of reliability and validity for new instruments, determine feasibility of recruitment and retention procedures, and evaluate use of a method to enhance social facilitation. Using a 2-group longitudinal design, a total of 160 women will be recruited and randomly assigned to a treatment or comparison group. Women in the treatment group will use TICI over an 8-week period of time. Measures of calcium and vitamin D will be obtained pre-intervention, immediately post and 3, and 6 months. Women's use of and satisfaction with the intervention will be measured. Equipment problems will be monitored. Groups will be compared for differences in calcium and vitamin D intake over time. Measures of select concepts (knowledge, self-efficacy, outcome expectancy, perceived risk, goal congruence) will be obtained and the relation ship among these concepts, the intervention and intake of calcium and vitamin D explored. ? ? ? ?