Micronutrient inadequacy and urinary stone disease: an analysis of the National Health and Nutrition Examination Survey 2007-2018.

Urinary stone disease is common and affects approximately 10% of the American adults. The role of diet in stone formation is well-recognized; however, the literature focus has been on dietary excess rather than micronutrient inadequacy. As patients with stones may be at risk for nutrient inadequacies, we investigated the role of micronutrient inadequacy in stone formation by performing a cross-sectional analysis of the National Health and Nutrition Examination Survey on adults who were not taking dietary supplements. Micronutrient intake was obtained from 24-h dietary recalls, and usual intake was calculated. Survey-weighted, adjusted logistic regression was used for an incident analysis on having any history of stones. An additional analysis on recurrent stone-formers was performed with the outcome being 2 or more stones passed. Finally, a sensitivity analysis using quasi-Poisson regression was performed with the outcome being number of stones passed. There were 9777 respondents representing 81,087,345 adults, of which 9.36% had a stone history. Our incident analysis revealed inadequate vitamin A intake to be associated with stone formation (OR 1.33, 95% CI: 1.03-1.71). Recurrent analysis did not find any significant associations, while our sensitivity analysis revealed inadequate vitamin A (IRR 1.96, 95% CI: 1.28-3.00) and pyridoxine (IRR 1.99, 95% CI: 1.11-3.55) to be associated with a higher number of recurrent stones. Hence, inadequate dietary intake of vitamin A and pyridoxine was associated with nephrolithiasis. Further research is needed to identify the roles of these micronutrients in stone-formers and the potential for evaluation and treatment.