This investigation found that young adult women (n = 265) were very likely (80.6%) to have accurate knowledge about osteoporosis but also typically had a low calcium intake (454 mg/day). The women in this study believed that they were at risk of osteoporosis but felt that prevention was difficult. Meanwhile, they held the opinion that osteoporosis is not serious and that taking preventative measures would not be worthwhile. The factors that most strongly affected the intake of calcium by women were, in order, knowledge, number of children, self-rated health score, Body Mass Index, graduation from high school, experience of bone density examination and family history. These seven items accounted for 31.8% of the variation in calcium intake.