Thank you so much for your suggestions. I can't use any minerals and some herb like nettle - because whenever I have in the past - it causes me pain because of my kidney problems.
But I am trying to strengthen them in different ways - with supplements and Homeopathic meds/remedies. And they are getting stronger. So maybe at a later time I can try it. I also cannot have caffeinated drinks in any form - tea, soda pop, coffee, etc - for the same reason - it causes me pain.
Currently I am using a lot of Homeopathic remedies that a knowlegeable friend of mine suggested and I am doing very well. Every week I can eat more of the things I couldn't before.