with my experiences, I have noticed that my body will sometimes get used to things, so they quit being as effective.Regarding the Caltrate Plus, I have noticed at different times, my body requires different dosages, who knows why. You might try going back on it and taking 3 pills per day, one with each meal you eat. Hopefully this will get you back on an even keel. I started at that and now, after a year of being on it, I fluctuate between one pill per day and two, usually one.Hope this helps some or someone else can give you some other advice.Hang in there.Christine------------------It is never too late to be what you might have been.----George Eliot