Although dialysis had the effect of lowering homocysteine levels, folic acid further reduced homocysteine levels and, more importantly, had long-term effects even after folic acid supplementation was withdrawn. Homocysteine concentrations remained decreased in 20 patients four weeks after withdrawal of folic acid supplementation. The occurrence of kidney stones is one of the most common of all kidney problems. Kidney stones are also one of the most painful of all health problems. Kidney stones are solid, rock-like materials that form from the mineral substances contained in the urine.
Most kidney stones consist of calcium combined with either oxalate or phosphate.
Less common types of kidney stones include a struvite, or infection, stone and the uric acid stone. Even more rare are kidney stones that are made up of cystine. Evidence shows that cystine-based stones tend to run in families. Kidney stones can grow to a size that can be life threatening or require surgery to remove. Some large kidney stones cannot be surgically removed due to the age of the patient and the danger of the associated trauma to a vital organ.