Nutrition is a key component of prevention for the most common types of kidney stones. The AUA Guidelines for the Medical Management of Kidney Stones include many nutrition-related recommendations, including increasing fruits and vegetables, reducing nondairy animal protein, inclusion of dietary calcium, and sodium reduction, depending on 24-hour urine chemistries and stone type (see Figure).¹ Urologists’ perception of the importance of nutrition for kidney stone formers is in line with these recommendations. A 2014 study found that 82% of urologists believe nutrition advice should be given to stone formers, regardless of number of stone events. However, less than 50% of urologists report assessing dietary intake before providing nutrition recommendations, and 36% feel they have insufficient time to provide nutrition education to patients.²

Registered dietitian nutritionists (RDNs) are uniquely trained to provide both nutrition education and counseling to patients for the prevention and treatment of chronic diseases. RDNs are the only health care professionals able to provide medical nutrition therapy (MNT), which includes a nutrition diagnosis and treatment plan to help patients make lifestyle changes to improve health outcomes. MNT provided by an RDN has been shown to improve outcomes related to a variety of health conditions such as chronic kidney disease.³ Conversely, nutrition education, or simply providing information, has not been shown to change behavior. In 2021, Betz et al found that higher knowledge of renal diet recommendations did not correlate with greater adherence in people with chronic kidney disease.⁴ However, counseling strategies such as motivational interviewing can induce behavior changes and improve health outcomes such as reduced hemoglobin A1c, cholesterol, and blood pressure.⁵ More research needs to be done to determine the effectiveness of MNT on kidney stone outcomes specifically.

RDNs have the time and skill to properly assess a patient’s current dietary intake, identify possible lithogenic eating patterns and/or supplementation, and personalize dietary recommendations for kidney stone prevention. Although 24-hour urine testing provides valuable information about consumption of nutrients such as fluid, sodium, protein, and potassium, only 1-3 days of intake are captured. Urine tests do not provide information about foods consumed, dietary patterns, or timing of meals. RDNs can help better understand patients’ long-term dietary patterns and foods consumed that contribute to nutrients of concern for kidney stone prevention to help make effective and realistic nutrition recommendations. Shared medical appointments in a kidney stone clinic that included an RDN have shown to improve 24-hour urine chemistries.⁶ In addition, RDNs can make nutrition recommendations considering a patient’s entire past medical history. This is especially important as comorbid conditions with nutrition considerations such as cardiovascular disease, hypertension, chronic kidney disease, and inflammatory bowel disease are common in people with kidney stones.⁷

Nutrition misinformation about kidney stones is prevalent. A 2021 study found that 23% of YouTube videos had inaccurate claims about kidney stones, and videos with inaccurate claims had more than twice the user engagement compared to videos with accurate claims.⁷ Nutrition was a common topic covered in YouTube videos; 28% discussed prevention including diet and hydration, and dietary supplements, natural remedies, and alternative medicine were promoted in 25% of the videos.⁸ In 2018, education materials provided in the emergency department were found to be a common source of nutrition misinformation, or inappropriate for people with kidney stones.⁹ RDNs can help reeducate patients about evidence-based strategies to prevent kidney stones, and direct patients to focus on strategies relevant to them, based on 24-hour urine studies. This could help improve patient confusion and frustration surrounding nutrition recommendations for stone prevention.

Despite the benefits, many barriers exist to the inclusion of RDNs in kidney stone clinics. Kidney stones are not a covered diagnosis for MNT by the Centers for Medicare and Medicaid Services. Coverage by private insurance payers varies. Patients may be required to pay out of pocket for RDN services if they are not subsidized by the urology clinic.

Registered dietitians are not necessarily trained in kidney stone prevention. There are no required competencies related to kidney stones in dietetic undergraduate or internship programs, as they are for disease states such as diabetes, obesity, or hypertension. As a result, many RDNs will require training to competently provide nutrition recommendations for kidney stone prevention. Given the high prevalence of nephrolithiasis, the Accreditation Council for Education in Nutrition and Dietetics should consider including a competency related to nephrolithiasis for accredited programs.

Lastly, RDNs are not currently available in most urology patients. Only 23% of urologists report partnering with an RDN,² and a 2014 survey found that only 8% of RDNs provide MNT for kidney stones as part of multidisciplinary clinic.¹⁰ A summary of the benefits and barriers to the inclusion of registered dietitians in kidney stone clinics is provided in the Table.

The urology community should work to increase the availability of RDNs for kidney stone patients. RDNs can help patients implement nutrition-related recommendations for kidney stone prevention, prevent kidney stone recurrence, and improve the health and well-being of patients.