Many companies produce calcium and Vitamin D, but this is the only company that goes the extra mile to include 3 additional vital minerals ( strontium, boron, Vitamin K) to actually make it a complete product. I also appreciate the high quality of ingredients, also not usually found in most products, along with what it does NOT contain. I must be very careful of soy. While it is higher priced than OTC products, I believe you get what you pay for and the cost matters MUCH less than quality. I have not been taking it long enough to have another bone density scan, but I am hopeful for better results in about 4 months.