Clinical Nutrition in Urologic Care

Hippocrates, frequently dubbed the founder of modern medicine, famously said “Let food be thy medicine and medicine be thy food.”


Recognizing the value of nutrition in urologic care, UW Health urologists actively promote clinical nutrition interventions to their patients and support a vibrant nutrition research program. Nutrition research is focused largely on nutritional approaches to prevent kidney stone recurrence, an area for which nutrition research to validate and inform best clinical practice has historically been lacking.


Nutrition research in the Department of Urology is multifaceted and includes epidemiologic and observational studies, food and supplement analysis, animal research and clinical interventions. Members of the Department were the first to publish decrements in the health-related quality of life of stone formers and recently developed an instrument to assess the quality of life of stone formers.


Dr. Kristina Penniston explains how drinking lemonade or lemon juice can help prevent kidney stones.In collaboration with animal science experts, Department researchers piloted a nutritional intervention in swine that has resulted in the formation of kidney stones, never before reported in pigs. This may evolve into a reliable animal model for the study of urolithiasis. Utilizing historical electronic medical records and population data from a regional epidemiologic database, the Department reported increased incidence of kidney stones with a narrowing of the gender gap.


Much of the Department’s nutrition research stems directly from patients’ needs and is aimed at optimizing the quality of their urologic care. After noting an increase in patients with kidney stones who had undergone a specific type of gastric bypass surgery commonly used to treat obesity, researchers collaborated with a bariatric surgeon to document the kidney stone risk factors in this population.


In response to a several month wait time for appointments in the UW Health Metabolic Stone Clinic, the Department piloted shared medical appointments for patients new to the clinic, decreasing by half the wait time from patients’ initial stone event to follow-up. In a collaborative study with Department of Medicine faculty, the Department of Urology found that vitamin D repletion for vitamin D insufficiency/deficiency does not increase urinary calcium excretion, contrary to conventional thought, and thus may not increase patients’ risk for forming calcium stones.


In other studies, Department researchers have confirmed the effectiveness of specific nutrition therapy to reduce patients’ urinary oxalate excretion and calcium oxalate supersaturation; identified lemon and lime juice as sources of citrate, an inhibitor of calcium stones; characterized patients’ attitudes toward medical management of their stones; evaluated the accuracy of 24-hour urinary stone risk parameters, a key diagnostic tool used in medical management; and identified specific components of patients’ diets that contribute to their stone recurrence risk.