Kidney stones, or nephrolithiasis, is a fairly common condition where certain types of mineral salts develop within the kidney forming small “stones”. These vary in size and may or may not cause any symptoms. Some stay within the kidney itself while others pass through the urinary tract and are excreted in the urine. Most of the time kidney stones become symptomatic when they travel into the lower urinary tract, and this pain can be tremendous until they are treated or actually pass out of your system.

            Most kidney stones are made of calcium and oxalate crystals. Oxalate is found in several foods, and consuming large quantities can increase the risk of developing stones. These foods include dark green vegetables, chocolate, rhubarb, nuts, beans, cranberries and a few other foods. A smaller percentage of stones are made mostly of uric acid which is elevated in people with gouty arthritis. Calcium stones are more common in people who have had intestinal surgeries and have difficulty absorbing fats or in individuals who may have altered parathyroid hormone conditions. Dehydration can lead to an increased risk of stone formation, and there is a genetic risk as well.

            In preventing their occurrence, it is important to remain well hydrated. Slowly building up to drinking 8-10 glasses of water a day is recommended, particularly if you are at an increased risk. Secondly avoiding foods high in oxalate content as listed above is encouraged. While calcium intake intuitively seems like it could worsen the risk of kidney stones, this may only be the case for a select number of people. Moderate to high amounts of calcium in the diet actually reduce the risk of kidney stones in some individuals. Lastly, making sure there are adequate amounts of fiber in your diet, and reducing added sodium are additional measures that are protective.

            For most people, it is also important to maintain adequate amounts of Vitamin B6 and magnesium in their diet. Both of these micronutrients assist the metabolism and elimination of oxalate, thereby reducing the risk of kidney stones. If supplemental forms of these are taken, 100mg of Vitamin B6 and 200mg of magnesium seem to be effective doses for stone prevention. Normal dietary intake of Vitamin C and D is healthy, but taking supplemental doses of these vitamins could actually increase the chances of kidney stones especially if you are higher risk. Grapefruit juice has actually been shown to increase risk, while citrate, which is high in some citrus juices, reduces the development of stone formation.

            Other conditions that promote kidney stone formation include frequent urinary infections and also diabetes or obesity. The latter two conditions are associated with insulin resistance. This in turn increases the amount of calcium excreted in the urine and increases the chances of nephrolithiasis. Also women who are post-menopausal or post-hysterectomy with lower estrogen levels have a greater tendency to forming stones. Some herbal nutrients like isoflavones found in soy products may be helpful in these individuals as they have some similar effects to estrogen.

            Overall, a great deal can be done to help reduce the chances of developing kidney stones. If you have a condition that puts you at greater risk, it is even more important to make dietary changes to help protect you. Hydration is by far the most important, followed by attention to the above aspects of one’s nutrition and mineral intake; certain vitamins also play a role.  Individuals who exercise have reduced rates of this condition. Taking these preventative measures may help you avoid this potentially painful disorder.