Some of the previous reviewer(s) obviously did not read the book. First of all, Barefoot quotes some of the Nobel Prize winners as well as other researchers and has admitted he backs their findings. Secondly, there is a lot of research proving the great benefits of calcium, not just naturalists. As with anything, different people's results will vary. Calcium was not discovered yesterday. To all the skeptics, where is your certificate of authenticity? Do you have proof that you know better? What research have you done? Those who say Calcium is bogus are not taking it in good form. This book provides a good source of info and explanation on Calcium and its necessity in life.