As the general public and the health care community have gained a greater understanding of the use of nutritional supplements to augment a person's diet and lifestyle, the number of people using these products have increased dramatically. While these nutritional supplements may be an important part of an individual's overall health care, recurrent stone formers must be cautious, as several of these products can increase the risk of recurrent stone formation. Patients who are at increased risk for calcium stone formation should avoid the use of 'mega dose' levels of vitamin C (ascorbic acid). The body is capable of breaking ascorbic acid into oxalate, which is then available to crystallize with calcium.
Additionally, patients at risk for calcium stones should avoid large doses of vitamin D. In its activated form, vitamin D causes the intestines to increase the amount of calcium absorbed from dietary sources.
Recurrent stone formers, especially those at high risk of uric acid stone formation, should use protein supplements cautiously. Protein supplements can vary widely as to the total amount of protein that is bio-available and also as to the type of protein used in the manufacturing process.
Recurrent calcium stone formers should use calcium supplements with caution. Although a diet with moderate amounts of calcium is encouraged, adding calcium from non-food sources is not. Recurrent kidney stone formers on long-term calcium supplement therapy increase their risk of recurrent calcium stone disease by approximately 20%.
A reasonable approach for recurrent stone formers who wish to use nutritional supplements would be to obtain the nutritional information about each of the products the patient is interested in using and reviewing it with their physician prior to starting its use. This will allow for maximizing the overall health benefits from these products while minimizing the chances of future stone formation.