@yerrag, I had issues (low level pains) with my kidneys for a while. When I noticed that I did not have them any longer, my best guess as to what might have helped was calcium: I had started to add eggshell powder to phosphate rich meals to balance the phosphate.
Peat mentioned that calcium can help with hypertension.
Need Help with Stubborn Hypertension
I came across this on Treating lead poisoning - an alternative therapist's view :
"...calcium has also been found effective in preventing the accumulation of lead in body tissues. This mechanism has been investigated by several university research teams. K.M. Six and R.A. Goyer found that reducing dietary calcium in rats greatly enhanced the body burden of lead, evidenced by increased levels in blood, bone and soft tissues.
C. Snowdon found that in calcium-deficient rats given water containing lead, lead replaced the lacking calcium in bones and teeth. Studies on rats (by L.G. Lederer and F.C. Bing) and on pigs (by F.Hsu and colleagues at Cornell University) indicate that adequate dietary calcium prevents re-accumulation of lead in body tissues by reducing absorption of ingested lead from the intestinal tract. Such evidence supports the view that calcium protects both water and body tissues from lead contamination."
Another + for calcium!