In abstract 1537 from the University of Wisconsin, researchers confirmed previous reports by Marshall Stoller's group from the University of San Francisco on the effectiveness of lemonade therapy (4 oz per day) in increasing urinary citrate levels in calcium oxalate (CaOx) stone formers. This study compared stone patients on potassium citrate plus lemonade therapy vs. lemonade therapy alone and followed them for more than three visits (3 months) in their metabolic stone clinic. Based on 24-hour urine evaluations, they determined that the lemonade therapy alone sustained higher urinary total volume and citrate levels compared to those patients on the combination of oral potassium citrate and lemonade therapy. In addition, they were able to maintain a favorable urinary pH in the patients treated with lemonade alone.
In addition, a study from Stony Brook, in a small group of patients (5), utilized an over-the-counter therapy called Theralith as an extended release nutritional supplement including magnesium oxide, magnesium citrate, potassium citrate, and pyridoxine (vit B6). Over the two month study period they found that there was a significant increase in urinary magnesium and citrate levels with this therapy. In addition, calcium oxalate supersaturation (SS CaOx) was significantly reduced in this patient population at one and two months follow-up. There was no information on urinary oxalate effect in the patients. However, of importance, while 60% of patients could not tolerate potassium citrate medication or diet modification, all of the patients in the Theralith group tolerated the nutritional supplement without any gastrointestinal side effects. These two simple dietary modifications in patients with CaOx stone disease suggest intriguing cost effective and durable therapy for CaOx stone formers. Further prospective randomized clinical trials are warranted with these dietary approaches to stone patient management.
