The effects of an educational intervention on calcium intake and bone mineral content in young women with low calcium intake.

PURPOSE This study evaluated whether a combined behavioral and dietary intervention would affect young women's calcium intake and bone mineral content (BMC). DESIGN The design was a two by three mixed design with one between-subjects factor (treatment vs. control) and one within-subjects factor (time--baseline, 3-month, and 6-month). SETTING The study was conducted in a university setting in Memphis, Tennessee. PARTICIPANTS A total of 80 premenopausal women (ages 18 to 30) with low baseline calcium intake (< 700 mg/d) were included in the analyses. There were 40 women in the treatment group and 40 women in the control group. MEASURES Hertzler and Frary's rapid assessment questionnaire was employed to evaluate calcium intake, and dual-energy x-ray absorptiometry (DEXA) was employed to assess BMC. RESULTS Repeated measures analysis of variance (RM ANOVA) was employed to analyze results. Results indicated that women in the treatment group made greater increases in total calcium intake and supplemental calcium than women in the control group and that all women made significant increases in dietary calcium intake. Additionally, analyses of BMC revealed that women in the treatment group did not experience significant changes in total BMC, and women in the control group experienced significant losses in total BMC. CONCLUSIONS In the current study, women were losing BMC, and the women who made the largest increases in calcium intake were able to retard this bone loss. There is increasing evidence that dietary calcium intake in young people is extremely low, and the results of the current study highlight the need for much more intensive evaluations investigating the factors that are positively associated with premenopausal bone mineral change.