I have lupus and suffer from anorexia off and on. I "tried" to take this a few years back and it made me very sick. My dr. said it's not the kind of vitamin that can be taken with just something to drink. It's so intense that you need to take it with food to buffer your stomach. I'm glad it's working for you and I hope you are having a healthy and active comeback from surgery. My brother had that same surgery and every once in a while his knee still gives him problems.