In order to perform community health activities during the university festival, pharmacy students gathered data and conducted lectures in the form of small group discussions (SGD). They measured participants’ bone densitometry, and then provided them with information about how to effectively prevent bone disease. The aim of this study is to assess whether students’ lectures on the “prevention of calcium-related disease” led participants in the University Festival to understand the following: (1) the benefits of absorption of calcium, (2) the risks of absorption of calcium, (3) which vegetables are calcium-rich, and (4) the risks of calcium overdose. First, participants responded to pretests comprising questions on the 4 above-mentioned topics. Next, they were subjected to bone density measurement, and pharmacy students explained the importance of “prevention of calcium-related disease.” Finally, participants carried out posttests (with the same contents as the pretests), and received advice based on the results of their posttests and bone densitometry measurements. Total scores on the posttests (98.4 points) were significantly higher than those on the pretests (53.3 points). Based on this, researchers concluded that the pharmacy students’ lectures substantially improved participants’ understandings about “prevention of calcium-related disease.”