I am 20 years post-op and have maintained my weight loss. I took all of the vitamins and B-12 but neglected the calcium. Well, after 5 broken vertebrae, collar bone and toe, I was diagnosed with osteoporosis. 10 months ago I started taking calcium citrate and extra D3 twice a day, and daily injections of Tymlos, I am close to normal with bone density. TAKE YOUR CALCIUM and VITAMINS!!!!