I have been using this product for over 15 years and it is by far the best! It has other essential vitamins and minerals that don't come with other calcium pills. I used to take prescription drugs for Osteoporosis, which made me feel like I was 100 yrs old. Along with exercise and Bone Up, I have reversed my Osteoporosis. I went from a negative 3.7 bone density (age 50) to negative 1.5 bone density for the last 5 years (since age 65) My doctor was amazed! I still have Osteopenia, but no longer have to take those horrible prescriptions that can prevent bone loss, but at the same time prevent your body from building NEW bone mass and cause other issues like horrible acid Reflux. Highly recommend it