He is 79 and in chronic kidney failure, had one cortisone shot in the lumbar, but did not help that much. HELP

Kidney problems can cause pain that is thought to be low back, however, since someone gave a cortisone shot, I presume they did an MRI scan and saw nerve impingement.

For nutritional management of pain, there is some information on the www.hufa.org website. Scroll down the first page and click on the pain link.